CVE-2026-71969
OP-TEE OS 4.10.0 Buffer Underwrite via RSA NOPAD Encrypt/Decrypt Operations
OP-TEE OS through 4.10.0, fixed in commit 7b8b494, contains a buffer underwrite vulnerability in the RSA NOPAD encrypt and decrypt operations within the mbedTLS software backend and SE050 hardware driver that allows a malicious Trusted Application to corrupt secure-world heap memory by supplying an input length exceeding the RSA modulus size. When src_len exceeds rsa_len, the subtraction expression wraps to a large unsigned value, causing a subsequent memcpy to write attacker-controlled data before the destination buffer in S-EL1 secure-world heap memory.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckFix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| optee_os OP-TEE OP-TEE/optee_os
github |
≥ 0; ≤ 4.10.0 (affected, semver) 7b8b494e0a324cefec8ed386b7de413b44f1aaf3 (unaffected, git) Other versions: affected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 8.4 high |
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 6.7 medium |
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H | CNA: VulnCheck |
Exploit evidence
- https://blog.secmate.dev/posts/optee-vulnerabilities-disclosure/
exploit · CNA: VulnCheck
References
- https://blog.secmate.dev/posts/optee-vulnerabilities-disclosure/CNA: VulnCheck · technical-description, exploit
- https://github.com/OP-TEE/optee_os/pull/7898CNA: VulnCheck · issue-tracking, patch
- https://github.com/OP-TEE/optee_os/pull/7808CNA: VulnCheck · issue-tracking, patch
- https://github.com/OP-TEE/optee_os/commit/7b8b494e0a324cefec8ed386b7de413b44f1aaf3CNA: VulnCheck · patch
- https://www.vulncheck.com/advisories/op-tee-os-buffer-underwrite-via-rsa-nopad-encrypt-decrypt-operationsCNA: VulnCheck · third-party-advisory
For agents and automation
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