Trusted application downgrade via zeroed subkey version
Published Jul 6, 2026 · Updated Jul 6, 2026
Improper authorization in OP-TEE OS 3.20.0 through 4.10.0 allows local users to load trusted applications signed by revoked subkeys. The shdr_load_pub_key() function parses each subkey header without copying subkey_version into the runtime key, so check_update_version() always receives zero and never advances the rollback database. Exploitation requires local low-privileged access and a mainline configuration using subkey-based trusted-application signing, enabling replacement with a downgraded chain that bypasses revocation and breaks trusted-application integrity.
Summary
What happened
Improper authorization in OP-TEE OS 3.20.0 through 4.10.0 allows local users to load trusted applications signed by revoked subkeys. The shdr_load_pub_key() function parses each subkey header without copying subkey_version into the runtime key, so check_update_version() always receives zero and never advances the rollback database. Exploitation requires local low-privileged access and a mainline configuration using subkey-based trusted-application signing, enabling replacement with a downgraded chain that bypasses revocation and breaks trusted-application integrity.
The record
- CVE
- CVE-2026-44362
- Published
- Jul 6, 2026
- Updated
- Jul 6, 2026
- Vendor
- OP-TEE
- Product
- OP-TEE OS
- Classifications
- CWE-285
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 6, 2026CVE publishedPublication date reported by the CVE source.
- Jul 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 3.20.0, < 4.11.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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