CVE-2026-54467: Trusted Firmware-M Privilege Escalation

CVE-2026-54467 Overview

CVE-2026-54467 affects Trusted Firmware-M (TF-M) versions 2 through 2.3.0 prior to commit 00d1b3e. The vulnerability resides in the mailbox initialization routine on the PSOC64 and RP2350 platforms. The routine accepts a non-secure, unvalidated, caller-supplied pointer and uses it without boundary checks. An attacker with local low-privileged access to the non-secure world can supply a pointer that references secure memory, breaking the isolation guarantee between secure and non-secure execution environments. The flaw is categorized as improper validation of an incoming pointer between trust domains [CWE-283].

Critical Impact
A crafted non-secure pointer passed to the mailbox init path can be dereferenced by the Secure Processing Environment, enabling disclosure or corruption of secure-world memory on PSOC64 and RP2350 devices.

Affected Products

Trusted Firmware-M (TF-M) versions 2.0 through 2.3.0 prior to commit 00d1b3e
PSOC64 platform builds using vulnerable TF-M mailbox initialization
RP2350 platform builds using vulnerable TF-M mailbox initialization

Discovery Timeline

2026-08-26 - CVE-2026-54467 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-54467

Vulnerability Analysis

Trusted Firmware-M provides the reference implementation of the Secure Processing Environment (SPE) for Armv8-M and adjacent platforms. The mailbox interface allows the Non-Secure Processing Environment (NSPE) to submit requests to secure services. During mailbox initialization on PSOC64 and RP2350, the SPE receives a pointer from the non-secure world and uses it without confirming that it references non-secure memory.

Because the SPE holds elevated privileges, dereferencing a caller-supplied address grants an attacker a primitive to read from or write to memory that the non-secure world should not touch. This defeats the fundamental isolation boundary that TF-M is designed to enforce.

Root Cause

The root cause is missing pointer origin validation in the mailbox init routine. The SPE must verify that any pointer received from the NSPE lies entirely within non-secure memory ranges and is properly aligned before dereferencing it. On the affected platforms, this check is absent, mapping to [CWE-283] Unverified Ownership.

Attack Vector

Exploitation requires local access to the non-secure world on a vulnerable PSOC64 or RP2350 device with low privileges. The attacker crafts a mailbox initialization request that embeds a pointer targeting secure memory. When the SPE processes the request, it operates on the attacker-chosen address, producing information disclosure, secure-state corruption, or denial of service. The CVSS vector indicates physical attack proximity with high attack complexity, reflecting the constrained embedded exploitation context.

No public exploit code or proof-of-concept has been observed. Technical details are described in the Trusted Firmware-M Security Advisory.

Detection Methods for CVE-2026-54467

Indicators of Compromise

Unexpected secure-fault or bus-fault exceptions logged by TF-M during or after mailbox initialization on PSOC64 or RP2350 targets.
Non-secure firmware components issuing mailbox init requests with pointer arguments that resolve outside declared non-secure RAM regions.
Anomalous device resets, hangs, or partition restarts correlated with NSPE-to-SPE mailbox traffic.

Detection Strategies

Audit TF-M build manifests and version strings on deployed devices to identify installations of versions 2.0 through 2.3.0 lacking commit 00d1b3e.
Instrument the SPE with runtime pointer-range assertions during development builds to surface non-secure pointers that fall outside expected memory maps.
Review vendor board support packages for PSOC64 and RP2350 to confirm inclusion of the upstream fix in shipping firmware.

Monitoring Recommendations

Collect device fault logs and telemetry into a centralized log store and alert on repeated secure-fault events tied to mailbox APIs.
Track firmware inventory and TF-M commit hashes as part of an asset management program for embedded fleets.
Monitor upstream Trusted Firmware-M advisories for follow-up disclosures affecting the same subsystem.

How to Mitigate CVE-2026-54467

Immediate Actions Required

Identify all PSOC64 and RP2350 devices running TF-M 2.0 through 2.3.0 and prioritize them for firmware update.
Apply the upstream TF-M fix at commit 00d1b3e or later, rebuild the SPE, and reflash affected devices.
Restrict physical and local access to affected embedded devices until updated firmware is deployed.

Patch Information

The fix is available in the Trusted Firmware-M upstream repository at commit 00d1b3e, which adds validation that pointers passed from the non-secure world during mailbox initialization reference non-secure memory. Review the Trusted Firmware-M Security Advisory for details, then integrate the patched TF-M into the platform build and validate through the standard TF-M regression tests before release.

Workarounds

Where patching is not immediately feasible, disable or constrain non-secure code paths that invoke mailbox initialization on PSOC64 and RP2350 targets.
Enforce secure boot and signed firmware policies to prevent loading of untrusted NSPE images that could reach the vulnerable code path.
Limit the set of non-secure clients permitted to interact with the SPE mailbox through platform-level access control.

bash

# Fetch and apply the upstream TF-M fix
git clone https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git
cd trusted-firmware-m
git checkout 00d1b3e
# Rebuild the secure image for the target platform (example: RP2350)
cmake -S . -B build -DTFM_PLATFORM=rpi/rp2350 -DTFM_PROFILE=profile_medium
cmake --build build -- install