diff --git a/components/esp_tee/subproject/main/arch/riscv/esp_tee_asm_utils.inc b/components/esp_tee/subproject/main/arch/riscv/esp_tee_asm_utils.inc
index 6478f02e13a..7e638cf55af 100644
--- a/components/esp_tee/subproject/main/arch/riscv/esp_tee_asm_utils.inc
+++ b/components/esp_tee/subproject/main/arch/riscv/esp_tee_asm_utils.inc
@@ -221,3 +221,35 @@
     1:
 #endif
 .endm
+
+/**
+ * VALIDATE_REE_SP
+ * Validate an REE-supplied sp before the TEE stores through it. The TEE region is
+ * at the bottom of SRAM, so a valid REE frame [sp - framesz, sp) must lie in the
+ * band above it and below the peripheral window: [SOC_S_DRAM_END, SOC_PERIPHERAL_LOW].
+ * An out-of-bound sp will lead to a fault.
+ *
+ * With chk_priv (default) the check is skipped unless the trap came from U-mode;
+ * pass chk_priv=0 where the U-mode origin is already guaranteed (ecall-from-U).
+ *
+ * TODO: Revisit these bounds for high-performance RISC-V SoCs (e.g. ESP32-P4,
+ * ESP32-S31) with different memory maps than current ESP-TEE targets.
+ *
+ * Clobbers: \tx
+ */
+.macro VALIDATE_REE_SP framesz, tx, chk_priv=1
+.if \chk_priv
+    /* Skip validation unless the previous privilege (mstatus.MPP) was U-mode */
+    csrr    \tx, mstatus
+    srli    \tx, \tx, MSTATUS_MPP_SHIFT
+    andi    \tx, \tx, (MSTATUS_MPP >> MSTATUS_MPP_SHIFT)
+    bnez    \tx, 1f
+.endif
+    li      \tx, (SOC_S_DRAM_END + \framesz)
+    bltu    sp, \tx, _tee_sp_reject      /* frame would dip into the TEE (or sub-TEE) region */
+    li      \tx, SOC_PERIPHERAL_LOW
+    bltu    \tx, sp, _tee_sp_reject      /* sp at/above the peripheral window */
+.if \chk_priv
+1:
+.endif
+.endm
diff --git a/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_clic.S b/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_clic.S
index bf64ea045d5..debc4f77a3d 100644
--- a/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_clic.S
+++ b/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_clic.S
@@ -25,6 +25,8 @@
     .equ ECALL_M_MODE, 0xb
     .equ CSR_UINTTHRESH, 0x047
     .equ CSR_MINTTHRESH, 0x347
+    .equ MCAUSE_EXCCODE_SHIFT, 20
+    .equ MSTATUS_MPP_SHIFT, 11
 
     .global esp_tee_global_interrupt_handler
     .global esp_tee_service_dispatcher
@@ -55,6 +57,10 @@ _ns_sp_min:
 _ns_sp_max:
     .word 0
 
+    .global _ns_int_rtn
+_ns_int_rtn:
+    .word 0
+
     .section .exception_vectors.text, "ax"
 
     /* Exception handler. */
@@ -62,28 +68,23 @@ _ns_sp_max:
     .global _tee_panic_handler
     .type _tee_panic_handler, @function
 _tee_exception_handler:
-    /* Backup t0, t1 on the stack before using it */
-    addi    sp, sp, -16
-    sw      t0, 0(sp)
-    sw      t1, 4(sp)
+    /* Backup t0 before using it */
+    csrw    mscratch, t0
 
-    /* Read mcause */
+    /* Check whether the exception is an M-mode/U-mode ecall */
     csrr    t0, mcause
-    li      t1, VECTORS_MCAUSE_REASON_MASK
-    and     t0, t0, t1
+    slli    t0, t0, MCAUSE_EXCCODE_SHIFT
+    srli    t0, t0, MCAUSE_EXCCODE_SHIFT
+    addi    t0, t0, -ECALL_M_MODE
+    beqz    t0, _machine_ecall              /* M-mode ecall */
+    addi    t0, t0, (ECALL_M_MODE - ECALL_U_MODE)
+    beqz    t0, _user_ecall                 /* U-mode ecall */
 
-    /* Check whether the exception is an M-mode ecall */
-    li      t1, ECALL_M_MODE
-    beq     t0, t1, _machine_ecall
+    /* Validate a U-mode-origin sp before the handler stores/dumps through it */
+    VALIDATE_REE_SP RV_STK_FRMSZ, t0
 
-    /* Check whether the exception is an U-mode ecall */
-    li      t1, ECALL_U_MODE
-    beq     t0, t1, _user_ecall
-
-    /* Restore t0, t1 from the stack */
-    lw      t0, 0(sp)
-    lw      t1, 4(sp)
-    addi    sp, sp, 16
+    /* Restore t0 */
+    csrr    t0, mscratch
 
 _tee_panic_handler:
     /* Not an ecall, proceed to the panic handler */
@@ -147,6 +148,12 @@ _return_from_exception:
     restore_general_regs RV_STK_FRMSZ
     mret
 
+    /* Fault if the sp given by the REE is found to be out-of-bounds */
+_tee_sp_reject:
+    csrr    t0, mscratch
+    la      sp, _tee_stack
+    j       _tee_panic_handler
+
     .size  _tee_exception_handler, .-_tee_exception_handler
 
     /* ECALL handler. */
@@ -211,14 +218,15 @@ _skip_ctx_restore:
     /* U-mode ecall handler */
 _user_ecall:
     /* Check whether we are returning after servicing an U-mode interrupt */
-    lui     t0, RTNVAL
-    csrrw   t1, mscratch, zero
-    beq     t0, t1, _rtn_from_ns_int
+    la      t0, _ns_int_rtn
+    lw      t0, 0(t0)
+    bnez    t0, _rtn_from_ns_int
 
-    /* Restore t0, t1 from the stack */
-    lw      t0, 0(sp)
-    lw      t1, 4(sp)
-    addi    sp, sp, 16
+    /* Reject an sp whose frame would be out-of-bounds */
+    VALIDATE_REE_SP CONTEXT_SIZE, t0, 0
+
+    /* Restore t0 */
+    csrr    t0, mscratch
 
     /* This point is reached when a secure service call is issued from the REE */
     /* Save register context and mepc */
@@ -272,6 +280,10 @@ _2:
     /* This point is reached after servicing a U-mode interrupt occurred
      * while executing a secure service */
 _rtn_from_ns_int:
+    /* Consume the U-mode-interrupt-return sentinel (checked in _user_ecall). */
+    la      t0, _ns_int_rtn
+    sw      zero, 0(t0)
+
     /* Disable the U-mode interrupt delegation */
     li      t0, INTMTX_SIG_IDX_ASSERT_IN_SEC_REG
     li      t1, TEE_PASS_INUM + CLIC_EXT_INTR_NUM_OFFSET
@@ -415,8 +427,9 @@ _4:
     fence
 
     /* Set a flag to identify the next U2M switch would be after handling a U-mode interrupt */
-    lui     t0, RTNVAL
-    csrw    mscratch, t0
+    la      t0, _ns_int_rtn
+    li      t1, RTNVAL
+    sw      t1, 0(t0)
 
     STACK_GUARD_POST_SWITCH t3 1 _ns_sp_min _ns_sp_max
 
@@ -435,6 +448,11 @@ _4:
     .global _tee_s_intr_handler
     .type _tee_s_intr_handler, @function
 _tee_s_intr_handler:
+    /* Check sp if trapped from U-mode */
+    csrw    mscratch, t0
+    VALIDATE_REE_SP RV_STK_FRMSZ, t0
+    csrr    t0, mscratch                                 /* restore the preempted t0 */
+
     /* Start by saving the general purpose registers and the PC value before
      * the interrupt happened. */
     save_general_regs RV_STK_FRMSZ
diff --git a/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_plic.S b/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_plic.S
index 1274e5df3d6..28437683e35 100644
--- a/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_plic.S
+++ b/components/esp_tee/subproject/main/arch/riscv/esp_tee_vectors_plic.S
@@ -23,6 +23,7 @@
     .equ RTNVAL, 0xc0de
     .equ ECALL_U_MODE, 0x8
     .equ ECALL_M_MODE, 0xb
+    .equ MSTATUS_MPP_SHIFT, 11
     /* NOTE: INTWDT timeout, Cache error and Stack protection interrupts
      * trigger the panic handler before reset, so they don't need to be delegated. */
     .equ TEE_INTR_DELEG_BASE, ((1U << TEE_SECURE_INUM) | (1U << ETS_INT_WDT_INUM) | (1U << ETS_CACHEERR_INUM))
@@ -60,6 +61,10 @@ _ns_sp_min:
 _ns_sp_max:
     .word 0
 
+    .global _ns_int_rtn
+_ns_int_rtn:
+    .word 0
+
     .section .exception_vectors.text, "ax"
 
     /* Exception handler. */
@@ -67,28 +72,22 @@ _ns_sp_max:
     .global _tee_panic_handler
     .type _tee_exception_handler, @function
 _tee_exception_handler:
-    /* Backup t0, t1 on the stack before using it */
-    addi    sp, sp, -16
-    sw      t0, 0(sp)
-    sw      t1, 4(sp)
+    /* Backup t0 before using it */
+    csrw    mscratch, t0
 
-    /* Read mcause */
+    /* Check whether the exception is an M-mode/U-mode ecall */
     csrr    t0, mcause
-    li      t1, VECTORS_MCAUSE_REASON_MASK
-    and     t0, t0, t1
+    andi    t0, t0, VECTORS_MCAUSE_REASON_MASK
+    addi    t0, t0, -ECALL_M_MODE
+    beqz    t0, _machine_ecall              /* M-mode ecall */
+    addi    t0, t0, (ECALL_M_MODE - ECALL_U_MODE)
+    beqz    t0, _user_ecall                 /* U-mode ecall */
 
-    /* Check whether the exception is an M-mode ecall */
-    li      t1, ECALL_M_MODE
-    beq     t0, t1, _machine_ecall
+    /* Validate a U-mode-origin sp before the handler stores/dumps through it */
+    VALIDATE_REE_SP RV_STK_FRMSZ, t0
 
-    /* Check whether the exception is an U-mode ecall */
-    li      t1, ECALL_U_MODE
-    beq     t0, t1, _user_ecall
-
-    /* Restore t0, t1 from the stack */
-    lw      t0, 0(sp)
-    lw      t1, 4(sp)
-    addi    sp, sp, 16
+    /* Restore t0 */
+    csrr    t0, mscratch
 
 _tee_panic_handler:
     /* Not an ecall, proceed to the panic handler */
@@ -143,6 +142,12 @@ _return_from_exception:
     restore_general_regs RV_STK_FRMSZ
     mret
 
+    /* Fault if the sp given by the REE is found to be out-of-bounds */
+_tee_sp_reject:
+    csrr    t0, mscratch
+    la      sp, _tee_stack
+    j       _tee_panic_handler
+
     .size  _tee_exception_handler, .-_tee_exception_handler
 
     /* ECALL handler. */
@@ -203,14 +208,15 @@ _skip_ctx_restore:
     /* U-mode ecall handler */
 _user_ecall:
     /* Check whether we are returning after servicing an U-mode interrupt */
-    lui     t0, RTNVAL
-    csrrw   t1, mscratch, zero
-    beq     t0, t1, _rtn_from_ns_int
+    la      t0, _ns_int_rtn
+    lw      t0, 0(t0)
+    bnez    t0, _rtn_from_ns_int
 
-    /* Restore t0, t1 from the stack */
-    lw      t0, 0(sp)
-    lw      t1, 4(sp)
-    addi    sp, sp, 16
+    /* Reject an sp whose frame would be out-of-bounds */
+    VALIDATE_REE_SP CONTEXT_SIZE, t0, 0
+
+    /* Restore t0 */
+    csrr    t0, mscratch
 
     /* This point is reached when a secure service call is issued from the REE */
     /* Save register context and mepc */
@@ -260,6 +266,10 @@ _process_ecall:
     /* This point is reached after servicing a U-mode interrupt occurred
      * while executing a secure service */
 _rtn_from_ns_int:
+    /* Consume the U-mode-interrupt-return sentinel (checked in _user_ecall). */
+    la      t0, _ns_int_rtn
+    sw      zero, 0(t0)
+
     /* Disable the U-mode interrupt delegation */
     csrwi    mideleg, 0
 
@@ -341,8 +351,9 @@ _tee_ns_intr_handler:
     fence
 
     /* Set a flag to identify the next U2M switch would be after handling a U-mode interrupt */
-    lui     t0, RTNVAL
-    csrw    mscratch, t0
+    la      t0, _ns_int_rtn
+    li      t1, RTNVAL
+    sw      t1, 0(t0)
 
     /* Enable the U-mode interrupt delegation (except for the TEE secure interrupt) */
     li      t0, TEE_INTR_DELEG_MASK
@@ -365,6 +376,11 @@ _tee_ns_intr_handler:
     .global _tee_s_intr_handler
     .type _tee_s_intr_handler, @function
 _tee_s_intr_handler:
+    /* Check sp if trapped from U-mode */
+    csrw    mscratch, t0
+    VALIDATE_REE_SP RV_STK_FRMSZ, t0
+    csrr    t0, mscratch                                 /* restore the preempted t0 */
+
     /* Start by saving the general purpose registers and the PC value before
      * the interrupt happened. */
     save_general_regs RV_STK_FRMSZ
diff --git a/components/esp_tee/subproject/main/include/esp_tee_memory_utils.h b/components/esp_tee/subproject/main/include/esp_tee_memory_utils.h
index e3ec2f50dfa..0d52b8fc636 100644
--- a/components/esp_tee/subproject/main/include/esp_tee_memory_utils.h
+++ b/components/esp_tee/subproject/main/include/esp_tee_memory_utils.h
@@ -16,19 +16,9 @@
 extern "C" {
 #endif
 
-FORCE_INLINE_ATTR bool esp_tee_ptr_in_ree(const void *p)
-{
-    uintptr_t addr = (uintptr_t)p;
-    return (
-               (addr >= SOC_NS_IDRAM_START && addr < SOC_NS_IDRAM_END) ||
-               (addr >= (uintptr_t)esp_tee_app_config.ns_drom_start &&
-                addr < SOC_S_MMU_MMAP_RESV_START_VADDR)
-#if SOC_RTC_MEM_SUPPORTED
-               || (addr >= SOC_RTC_DATA_LOW && addr < SOC_RTC_DATA_HIGH)
-#endif
-           );
-}
-
+/* TODO: Revisit these bounds for high-performance RISC-V SoCs (e.g. ESP32-P4,
+ * ESP32-S31) with different memory maps than current ESP-TEE targets.
+ */
 FORCE_INLINE_ATTR bool esp_tee_buf_in_ree(const void *p, size_t len)
 {
     uintptr_t start = (uintptr_t)p;
@@ -40,13 +30,18 @@ FORCE_INLINE_ATTR bool esp_tee_buf_in_ree(const void *p, size_t len)
 
     uintptr_t end = start + len;
     return ((start >= SOC_NS_IDRAM_START && end <= SOC_NS_IDRAM_END) ||
-            (start >= (uintptr_t)esp_tee_app_config.ns_drom_start && end <= SOC_S_MMU_MMAP_RESV_START_VADDR)
+            (start >= SOC_S_DROM_HIGH && end <= SOC_S_MMU_MMAP_RESV_START_VADDR)
 #if SOC_RTC_MEM_SUPPORTED
             || (start >= SOC_RTC_DATA_LOW && end <= SOC_RTC_DATA_HIGH)
 #endif
            );
 }
 
+FORCE_INLINE_ATTR bool esp_tee_ptr_in_ree(const void *p)
+{
+    return esp_tee_buf_in_ree(p, 4);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/esp_tee/subproject/main/soc/esp32c5/esp_tee_pmp_pma_prot_cfg.c b/components/esp_tee/subproject/main/soc/esp32c5/esp_tee_pmp_pma_prot_cfg.c
index f7d47af6365..3947a6e72f2 100644
--- a/components/esp_tee/subproject/main/soc/esp32c5/esp_tee_pmp_pma_prot_cfg.c
+++ b/components/esp_tee/subproject/main/soc/esp32c5/esp_tee_pmp_pma_prot_cfg.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2023-2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2023-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -55,9 +55,9 @@ static void esp_tee_configure_invalid_regions(void)
 
     // 7. Using PMA to configure the TEE text and data section access attribute. */
     PMA_ENTRY_CFG_RESET(12);
-    assert(IS_PMA_ENTRY_UNLOCKED(13));
-    assert(IS_PMA_ENTRY_UNLOCKED(14));
-    assert(IS_PMA_ENTRY_UNLOCKED(15));
+    ESP_FAULT_ASSERT(IS_PMA_ENTRY_UNLOCKED(13) &&
+                     IS_PMA_ENTRY_UNLOCKED(14) &&
+                     IS_PMA_ENTRY_UNLOCKED(15));
 
     extern int _tee_iram_end;
     PMA_RESET_AND_ENTRY_SET_TOR(13, SOC_S_IRAM_START, PMA_NONE);
@@ -122,6 +122,20 @@ void esp_tee_configure_region_protection(void)
     PMP_ENTRY_CFG_RESET(4);
     PMP_ENTRY_CFG_RESET(5);
     PMP_ENTRY_CFG_RESET(6);
+    /* Validate the REE-supplied (esp_tee_app_config) bounds before programming
+     * the TOR-chained PMP entries below */
+    const uint32_t ns_iram_end      = (uint32_t)esp_tee_app_config.ns_iram_end;
+    const uint32_t s_irom_resv_end  = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
+    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
+    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
+    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
+
+    ESP_FAULT_ASSERT(ns_iram_end >= SOC_NS_IRAM_START &&
+                     ns_iram_end <= SOC_DRAM_HIGH &&
+                     s_irom_resv_end <= ns_irom_resv_end &&
+                     ns_irom_resv_end <= ns_drom_resv_end &&
+                     ns_drom_resv_end <= ns_drom_mmap_end);
+
     if (esp_cpu_dbgr_is_attached()) {
         // Anti-FI check that cpu is really in ocd mode
         ESP_FAULT_ASSERT(esp_cpu_dbgr_is_attached());
@@ -131,15 +145,10 @@ void esp_tee_configure_region_protection(void)
     } else {
         // REE SRAM (D/IRAM)
         PMP_ENTRY_SET(4, (int)SOC_NS_IRAM_START, NONE);
-        PMP_ENTRY_SET(5, (int)esp_tee_app_config.ns_iram_end, PMP_TOR | RX);
+        PMP_ENTRY_SET(5, (int)ns_iram_end, PMP_TOR | RX);
         PMP_ENTRY_SET(6, SOC_DRAM_HIGH, PMP_TOR | RW);
     }
 
-    const uint32_t s_irom_resv_end = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
-    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
-    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
-    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
-
     // 4. I_Cache / D_Cache (flash) - REE
     PMP_ENTRY_CFG_RESET(7);
     PMP_ENTRY_CFG_RESET(8);
diff --git a/components/esp_tee/subproject/main/soc/esp32c6/esp_tee_pmp_pma_prot_cfg.c b/components/esp_tee/subproject/main/soc/esp32c6/esp_tee_pmp_pma_prot_cfg.c
index bea234af031..4f977647f59 100644
--- a/components/esp_tee/subproject/main/soc/esp32c6/esp_tee_pmp_pma_prot_cfg.c
+++ b/components/esp_tee/subproject/main/soc/esp32c6/esp_tee_pmp_pma_prot_cfg.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -63,9 +63,9 @@ static void esp_tee_configure_invalid_regions(void)
     PMA_RESET_AND_ENTRY_SET_TOR(12, UINT32_MAX, PMA_TOR | PMA_NONE);
 
     // 8. Using PMA to configure the TEE text and data section access attribute. */
-    assert(IS_PMA_ENTRY_UNLOCKED(13));
-    assert(IS_PMA_ENTRY_UNLOCKED(14));
-    assert(IS_PMA_ENTRY_UNLOCKED(15));
+    ESP_FAULT_ASSERT(IS_PMA_ENTRY_UNLOCKED(13) &&
+                     IS_PMA_ENTRY_UNLOCKED(14) &&
+                     IS_PMA_ENTRY_UNLOCKED(15));
 
     extern int _tee_iram_end;
     PMA_RESET_AND_ENTRY_SET_TOR(13, SOC_S_IRAM_START, PMA_NONE);
@@ -112,7 +112,20 @@ void esp_tee_configure_region_protection(void)
     PMP_ENTRY_SET(1, SOC_IROM_MASK_HIGH, PMP_TOR | RX);
     _Static_assert(SOC_IROM_MASK_LOW < SOC_IROM_MASK_HIGH, "Invalid I/D-ROM region");
 
-    /* TODO: Check whether changes are required here */
+    /* Validate the REE-supplied (esp_tee_app_config) bounds before programming
+     * the TOR-chained PMP entries below */
+    const uint32_t ns_iram_end      = (uint32_t)esp_tee_app_config.ns_iram_end;
+    const uint32_t s_irom_resv_end  = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
+    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
+    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
+    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
+
+    ESP_FAULT_ASSERT(ns_iram_end >= SOC_NS_IRAM_START &&
+                     ns_iram_end <= SOC_DRAM_HIGH &&
+                     s_irom_resv_end <= ns_irom_resv_end &&
+                     ns_irom_resv_end <= ns_drom_resv_end &&
+                     ns_drom_resv_end <= ns_drom_mmap_end);
+
     if (esp_cpu_dbgr_is_attached()) {
         // Anti-FI check that cpu is really in ocd mode
         ESP_FAULT_ASSERT(esp_cpu_dbgr_is_attached());
@@ -125,15 +138,10 @@ void esp_tee_configure_region_protection(void)
         // 2. IRAM and DRAM
         // Splitting the REE SRAM region into IRAM and DRAM
         PMP_ENTRY_SET(2, (int)SOC_NS_IRAM_START, NONE);
-        PMP_ENTRY_SET(3, (int)esp_tee_app_config.ns_iram_end, PMP_TOR | RX);
+        PMP_ENTRY_SET(3, (int)ns_iram_end, PMP_TOR | RX);
         PMP_ENTRY_SET(4, SOC_DRAM_HIGH, PMP_TOR | RW);
     }
 
-    const uint32_t s_irom_resv_end = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
-    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
-    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
-    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
-
     // 4. I_Cache / D_Cache (flash) - REE
     PMP_ENTRY_CFG_RESET(5);
     PMP_ENTRY_CFG_RESET(6);
diff --git a/components/esp_tee/subproject/main/soc/esp32c61/esp_tee_pmp_pma_prot_cfg.c b/components/esp_tee/subproject/main/soc/esp32c61/esp_tee_pmp_pma_prot_cfg.c
index 26c8116cf94..a574db48a7a 100644
--- a/components/esp_tee/subproject/main/soc/esp32c61/esp_tee_pmp_pma_prot_cfg.c
+++ b/components/esp_tee/subproject/main/soc/esp32c61/esp_tee_pmp_pma_prot_cfg.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2025-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -55,9 +55,9 @@ static void esp_cpu_configure_invalid_regions(void)
 
     // 8. Using PMA to configure the TEE text and data section access attribute. */
     PMA_ENTRY_CFG_RESET(12);
-    assert(IS_PMA_ENTRY_UNLOCKED(13));
-    assert(IS_PMA_ENTRY_UNLOCKED(14));
-    assert(IS_PMA_ENTRY_UNLOCKED(15));
+    ESP_FAULT_ASSERT(IS_PMA_ENTRY_UNLOCKED(13) &&
+                     IS_PMA_ENTRY_UNLOCKED(14) &&
+                     IS_PMA_ENTRY_UNLOCKED(15));
 
     extern int _tee_iram_end;
     PMA_RESET_AND_ENTRY_SET_TOR(13, SOC_S_IRAM_START, PMA_NONE);
@@ -121,6 +121,20 @@ void esp_tee_configure_region_protection(void)
     PMP_ENTRY_CFG_RESET(4);
     PMP_ENTRY_CFG_RESET(5);
     PMP_ENTRY_CFG_RESET(6);
+    /* Validate the REE-supplied (esp_tee_app_config) bounds before programming
+     * the TOR-chained PMP entries below */
+    const uint32_t ns_iram_end      = (uint32_t)esp_tee_app_config.ns_iram_end;
+    const uint32_t s_irom_resv_end  = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
+    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
+    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
+    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
+
+    ESP_FAULT_ASSERT(ns_iram_end >= SOC_NS_IRAM_START &&
+                     ns_iram_end <= SOC_DRAM_HIGH &&
+                     s_irom_resv_end <= ns_irom_resv_end &&
+                     ns_irom_resv_end <= ns_drom_resv_end &&
+                     ns_drom_resv_end <= ns_drom_mmap_end);
+
     if (esp_cpu_dbgr_is_attached()) {
         // Anti-FI check that cpu is really in ocd mode
         ESP_FAULT_ASSERT(esp_cpu_dbgr_is_attached());
@@ -130,15 +144,10 @@ void esp_tee_configure_region_protection(void)
     } else {
         // REE SRAM (D/IRAM)
         PMP_ENTRY_SET(4, (int)SOC_NS_IRAM_START, NONE);
-        PMP_ENTRY_SET(5, (int)esp_tee_app_config.ns_iram_end, PMP_TOR | RX);
+        PMP_ENTRY_SET(5, (int)ns_iram_end, PMP_TOR | RX);
         PMP_ENTRY_SET(6, SOC_DRAM_HIGH, PMP_TOR | RW);
     }
 
-    const uint32_t s_irom_resv_end = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
-    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
-    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
-    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
-
     // 4. I_Cache / D_Cache (flash) - REE
     PMP_ENTRY_CFG_RESET(7);
     PMP_ENTRY_CFG_RESET(8);
diff --git a/components/esp_tee/subproject/main/soc/esp32h2/esp_tee_pmp_pma_prot_cfg.c b/components/esp_tee/subproject/main/soc/esp32h2/esp_tee_pmp_pma_prot_cfg.c
index 8de916768ce..5c7d3acd54b 100644
--- a/components/esp_tee/subproject/main/soc/esp32h2/esp_tee_pmp_pma_prot_cfg.c
+++ b/components/esp_tee/subproject/main/soc/esp32h2/esp_tee_pmp_pma_prot_cfg.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2025-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -65,9 +65,9 @@ static void esp_tee_configure_invalid_regions(void)
     PMA_ENTRY_SET_TOR(12, UINT32_MAX, PMA_TOR | PMA_NONE);
 
     /* 8. Using PMA to configure the TEE text and data section access attribute. */
-    assert(IS_PMA_ENTRY_UNLOCKED(13));
-    assert(IS_PMA_ENTRY_UNLOCKED(14));
-    assert(IS_PMA_ENTRY_UNLOCKED(15));
+    ESP_FAULT_ASSERT(IS_PMA_ENTRY_UNLOCKED(13) &&
+                     IS_PMA_ENTRY_UNLOCKED(14) &&
+                     IS_PMA_ENTRY_UNLOCKED(15));
 
     extern int _tee_iram_end;
     PMA_RESET_AND_ENTRY_SET_TOR(13, SOC_S_IRAM_START, PMA_NONE);
@@ -108,7 +108,20 @@ void esp_tee_configure_region_protection(void)
     PMP_ENTRY_SET(0, pmpaddr0, PMP_NAPOT | RX);
     _Static_assert(SOC_IROM_MASK_LOW < SOC_IROM_MASK_HIGH, "Invalid I/D-ROM region");
 
-    /* TODO: Check whether changes are required here */
+    /* Validate the REE-supplied (esp_tee_app_config) bounds before programming
+     * the TOR-chained PMP entries below */
+    const uint32_t ns_iram_end      = (uint32_t)esp_tee_app_config.ns_iram_end;
+    const uint32_t s_irom_resv_end  = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
+    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
+    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
+    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
+
+    ESP_FAULT_ASSERT(ns_iram_end >= SOC_NS_IRAM_START &&
+                     ns_iram_end <= SOC_DRAM_HIGH &&
+                     s_irom_resv_end <= ns_irom_resv_end &&
+                     ns_irom_resv_end <= ns_drom_resv_end &&
+                     ns_drom_resv_end <= ns_drom_mmap_end);
+
     if (esp_cpu_dbgr_is_attached()) {
         // Anti-FI check that cpu is really in ocd mode
         ESP_FAULT_ASSERT(esp_cpu_dbgr_is_attached());
@@ -121,15 +134,10 @@ void esp_tee_configure_region_protection(void)
         // 2. IRAM and DRAM
         // Splitting the REE SRAM region into IRAM and DRAM
         PMP_ENTRY_SET(1, (int)SOC_NS_IRAM_START, NONE);
-        PMP_ENTRY_SET(2, (int)esp_tee_app_config.ns_iram_end, PMP_TOR | RX);
+        PMP_ENTRY_SET(2, (int)ns_iram_end, PMP_TOR | RX);
         PMP_ENTRY_SET(3, SOC_DRAM_HIGH, PMP_TOR | RW);
     }
 
-    const uint32_t s_irom_resv_end = SOC_IROM_LOW + CONFIG_SECURE_TEE_IROM_SIZE + CONFIG_SECURE_TEE_DROM_SIZE;
-    const uint32_t ns_irom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_irom_end);
-    const uint32_t ns_drom_resv_end = ALIGN_UP_TO_MMU_PAGE_SIZE((uint32_t)esp_tee_app_config.ns_drom_end);
-    const uint32_t ns_drom_mmap_end = (uint32_t)(SOC_S_MMU_MMAP_RESV_START_VADDR);
-
     // 4. I_Cache / D_Cache (flash) - REE
     PMP_ENTRY_CFG_RESET(5);
     PMP_ENTRY_CFG_RESET(6);
diff --git a/components/esp_tee/test_apps/tee_test_fw/main/CMakeLists.txt b/components/esp_tee/test_apps/tee_test_fw/main/CMakeLists.txt
index af0c5563825..9c8e4c6e968 100644
--- a/components/esp_tee/test_apps/tee_test_fw/main/CMakeLists.txt
+++ b/components/esp_tee/test_apps/tee_test_fw/main/CMakeLists.txt
@@ -1,6 +1,6 @@
 idf_build_get_property(idf_path IDF_PATH)
 
-set(priv_requires bootloader_support esp_driver_gptimer esp_tee esp_timer mbedtls spi_flash)
+set(priv_requires bootloader_support esp_driver_gptimer esp_system esp_tee esp_timer mbedtls spi_flash)
 # Test FW related
 list(APPEND priv_requires nvs_flash test_utils unity)
 # TEE related
diff --git a/components/esp_tee/test_apps/tee_test_fw/main/test_esp_tee_panic.c b/components/esp_tee/test_apps/tee_test_fw/main/test_esp_tee_panic.c
index 79382076166..63f004d011d 100644
--- a/components/esp_tee/test_apps/tee_test_fw/main/test_esp_tee_panic.c
+++ b/components/esp_tee/test_apps/tee_test_fw/main/test_esp_tee_panic.c
@@ -29,6 +29,7 @@
 
 #include "unity.h"
 #include "esp_tee.h"
+#include "esp_private/hw_stack_guard.h"
 #include "secure_service_num.h"
 
 #define ALIGN_DOWN_TO_MMU_PAGE_SIZE(addr)  ((addr) & ~((SOC_MMU_PAGE_SIZE) - 1))
@@ -229,6 +230,25 @@ TEST_CASE("Test REE-TEE isolation: DROM-W1", "[exception]")
     TEST_FAIL_MESSAGE("Exception should have been generated");
 }
 
+TEST_CASE("Test REE-TEE isolation: Corrupted SP", "[exception]")
+{
+    uintptr_t atk_sp = (uintptr_t)&_iram_start - 0x100;
+
+    /* Disable U-mode interrupts so the tick cannot preempt before the ecall */
+    __asm__ volatile("csrci ustatus, 0x1\n\t" : : : "memory");
+
+    /* Stop the REE-owned HW stack guard, as a malicious REE could */
+#if CONFIG_ESP_SYSTEM_HW_STACK_GUARD
+    esp_hw_stack_guard_monitor_stop();
+#endif
+
+    /* Cross into the TEE with the doctored sp; the handler rejects it and panics */
+    __asm__ volatile("mv sp, %0\n\t"
+                     "ecall\n\t" : : "r"(atk_sp) : "memory");
+
+    TEST_FAIL_MESSAGE("Exception should have been generated");
+}
+
 static void do_stack_overflow(int depth, volatile uint8_t *sink)
 {
     if (depth == -1) {
diff --git a/components/esp_tee/test_apps/tee_test_fw/tee_exception_test_map.py b/components/esp_tee/test_apps/tee_test_fw/tee_exception_test_map.py
index 7590bae9469..b53d7d5df9c 100644
--- a/components/esp_tee/test_apps/tee_test_fw/tee_exception_test_map.py
+++ b/components/esp_tee/test_apps/tee_test_fw/tee_exception_test_map.py
@@ -23,6 +23,7 @@ _BASE_CONFIG = {
         'DROM-R1': 'Load access fault',
         'DROM-W1': 'Store access fault',
         'MMU-spillover': 'Illegal instruction',
+        'Corrupted SP': 'Environment call from U-mode',
     },
     'apm_violation': {
         'eFuse': 'APM - Space exception',