🛡️ CVE-2026-40257 — op-tee

🟡 CVSS 5.5 — Medium ✅ No Known Exploit CWE-787 NVD
5.5
CVSS Score
0 Low4 Medium7 High9 Critical10

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 3.21.0 and prior to version 4.11.0, the ARM Crypto Extensions accelerated SHA-3 implementation has an off-by-one error that can cause a massive heap overflow that corrupts all TEE kernel memory following the hash state. This affects all platforms built with CFG_CRYPTO_WITH_CE82=y (ARMv8.2+ with SHA3 Crypto Extensions). Version 4.11.0 contains a patch. As a workaround, disable SHA3 Crypto Extensions with CFG_CRYPTO_WITH_CE82=n.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Weakness class

CVE-2026-40257 is classified as CWE-787: Out-of-bounds Write. Data is written past the end or before the start of a buffer, corrupting whatever is stored there.

Affected software

CVE-2026-40257 is recorded against 1 package.

  • op-tee (from 3.21.0 up to 4.10.0)

Timeline and source

Published on 6 July 2026 and last revised on 7 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com

Details

Severity MEDIUM
CVSS Score 5.5
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE CWE-787
Public Exploit ✅ No
Source NVD
Published 2026-07-06
Updated 2026-08-11
Modified 2026-07-07

Affected Packages

Software From version Fixed in
op-tee 3.21.0 4.10.0

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