CVE-2026-71969 OP-TEE CVE debrief

Who should care

Defenders responsible for the security of systems utilizing OP-TEE OS, especially those deploying Trusted Applications, should be aware of this vulnerability. The potential for corruption of secure-world heap memory could lead to security issues, making it crucial to assess exposure and apply necessary fixes.

Why it matters

This vulnerability allows a malicious Trusted Application to corrupt secure-world heap memory, potentially leading to security issues. Defenders should verify the presence of this vulnerability in their OP-TEE OS deployments, especially where Trusted Applications are executed, and assess the potential impact.

• Corruption of secure-world heap memory by a malicious Trusted Application.
• Potential for security issues due to attacker-controlled data being written to secure memory.
• Need for verification of OP-TEE OS version and deployment context to assess exposure.
• Priority on applying the fix from commit 7b8b494 to prevent exploitation.

Technical summary

The buffer underwrite vulnerability in OP-TEE OS through version 4.10.0 arises from the RSA NOPAD encrypt and decrypt operations within the mbedTLS software backend and SE050 hardware driver. A malicious Trusted Application can exploit this by providing an input length that exceeds the RSA modulus size, leading to a subtraction expression that wraps to a large unsigned value. This causes a subsequent memcpy operation to write attacker-controlled data before the destination buffer in S-EL1 secure-world heap memory, potentially corrupting it.

Defensive priority

Defenders should prioritize verifying the presence of this vulnerability in their OP-TEE OS deployments, especially in environments where Trusted Applications are executed, and assess the potential impact on secure-world heap memory.

Recommended defensive actions

• Verify the version of OP-TEE OS in use and check if it is prior to the fixed version.
• Assess the deployment context to determine if Trusted Applications are executed and could potentially exploit this vulnerability.
• Review the secure-world heap memory management to understand potential exposure.
• Apply the fix from commit 7b8b494 if the current version of OP-TEE OS is vulnerable.
• Perform an inventory of assets that use OP-TEE OS to identify potential exposure.
• Monitor for suspicious activity related to Trusted Applications and secure-world heap memory.
• Track and review changes to OP-TEE OS deployments to ensure timely application of security updates.

Evidence notes

The vulnerability is confirmed to exist in OP-TEE OS versions up to 4.10.0. The issue is addressed in commit 7b8b494. However, the exact versions affected and the completeness of the fix require verification from official sources.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.