CVE-2026-42546: op-tee DoS — Fix

Description

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.3.0 and prior to version 4.11.0, a resource leak exists in OP-TEE’s shared memory cleanup logic because the function `cleanup_shm_refs()` in `core/tee/entry_std.c` fails to apply a required bitmask (`OPTEE_MSG_ATTR_TYPE_MASK`) to parameter attributes. When processing non-contiguous memory parameters from a normal-world caller, the system fails to match the attribute type in its internal switch statement and skips the necessary mobj_put() call. This results in a persistent reference leak of `mobj_reg_shm` objects, which remain on internal lists with dangling refcounts. This affects non-FF-A configurations that support non-contiguous, non-secure shared memory. Over time, these accumulated leaks progressively consume the secure-world heap, degrading the system's ability to service trusted application operations and eventually requiring a reboot to recover. Version 4.11.0 contains a patch. No known workarounds are available.

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CVSS v3.1 Score

3.8

LOW

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0011

Probability of exploitation

0.01%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor	Product	Versions
trustedfirmware	op-tee	3.3.0 — 4.10.0

References

Advisories & Patches

https://github.com/OP-TEE/optee_os/security/advisories/GHSA-c7j8-fgqw-rcgp

Frequently Asked Questions

What is CVE-2026-42546? +

OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. Starting in version 3.3.0 and prior to version 4.11.0, a resource leak exists in OP-TEE’s shared memory cleanup logic because the function `cleanup_shm_refs()` in `core/tee/entry_std.c` fails to apply a required bitmask (`OPTEE_MSG_ATTR_TYPE_MASK`) to parameter attributes. When processing non-contiguous memory parameters from a normal-world caller, the system fails to match the attribute type in its internal switch statement and skips the necessary mobj_put() call. This results in a persistent reference leak of `mobj_reg_shm` objects, which remain on internal lists with dangling refcounts. This affects non-FF-A configurations that support non-contiguous, non-secure shared memory. Over time, these accumulated leaks progressively consume the secure-world heap, degrading the system's ability to service trusted application operations and eventually requiring a reboot to recover. Version 4.11.0 contains a patch. No known workarounds are available. It has a CVSS v3.1 base score of 3.8 (LOW).

How severe is CVE-2026-42546? +

CVE-2026-42546 has a CVSS v3.1 score of 3.8 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0011, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-42546? +

CVE-2026-42546 affects products from trustedfirmware, specifically: op-tee. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-42546? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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