wolfEngine reuses the AES-CCM nonce on TLS 1.2 / DTLS 1.2 records
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
wolfEngine before 1.4.1 sources the explicit AES-CCM nonce for TLS 1.2 and DTLS 1.2 records from the record input buffer instead of the TLS sequence number carried in the additional authenticated data. Because the record layer leaves the explicit-nonce field for the cipher to populate, the value read is constant across records, so every AES-CCM record within a connection is encrypted under an identical key and nonce pair. Reusing a CCM key and nonce weakens confidentiality (identical keystream across records, so a known record recovers the others) and integrity (authentication tag forgery). Only wolfEngine is affected; wolfProvider is not. AES-GCM under wolfEngine is tracked separately. AES-CCM cipher suites are not enabled by default and must be explicitly selected, which limits exposure. TLS 1.3 and non-TLS use of the cipher are not affected.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-81341
- 2026-10-03 Alias added: GHSA-vf9h-5c79-c2xp
References
Advisory 1
More wolfSSL Wolfengine vulnerabilities
- TI-2026-56033 wolfEngine reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record CVSS 3.1HIGH 7.4
Sources
- CVE-2026-81341 · CVE Program
- CVE-2026-81341 · NVD
- FIRST EPSS
- GHSA-vf9h-5c79-c2xp · GitHub Advisory Database · CC BY 4.0
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