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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (OP-TEE Optee Os).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.4 | CVSS 4.0 | High | — | — | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 8.4 | CVSS 4.0 | High | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
| 6.7 | CVSS 3.1 | Medium | 0.8 | 5.9 | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 6.7 | CVSS 3.1 | Medium | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H (score shown at the top: disclosure@vulncheck.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · op-tee/optee os
- SSVC assessment updated
- Record published
- CVSS changed · 6.7
- Source status changed · → Awaiting Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-71968 OP-TEE OS 4.10.0 Use-After-Free via Trusted Application Loader TA_FLAG_CONCURRENT Aug 10, 2026
- Medium CVE-2026-71967 OP-TEE OS 4.10.0 NULL Pointer Dereference DoS via Widevine PTA open_session Aug 10, 2026
- Low CVE-2026-53763 OP-TEE has AES-GCM 32-bit integer overflow in length counters that breaks authentication guarantee Jul 6, 2026
- Medium CVE-2026-44362 OP-TEE's subkey rollback protection can be bypassed with older subkey versions Jul 6, 2026
- Low CVE-2026-42546 OP-TEE has missing OPTEE_MSG_ATTR_TYPE_MASK in cleanup_shm_refs() leaks mobj references Jul 6, 2026
- Low CVE-2026-41516 OP-TEE: Hisilicon HPRE PKCS#1 v1.5 Decryption Padding Oracle Jul 6, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-71969 is "OP-TEE OS 4.10.0 Buffer Underwrite via RSA NOPAD Encrypt/Decrypt Operations", rated Medium. It affects Optee Os (OP-TEE); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.7 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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