CVE-2026-81341

wolfEngine reuses the AES-CCM nonce on TLS 1.2 / DTLS 1.2 records

Published Aug 28, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Upgrade to wolfEngine 1.4.1, which sources the explicit AES-CCM nonce from the TLS sequence number. As an interim mitigation do not enable AES-CCM cipher suites, or use TLS 1.3.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:2.3:a:wolfssl:wolfengine:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Wolfssl
Wolfssl wolfengine
Vendors & Products Wolfssl
Wolfssl wolfengine
Type Values Removed Values Added
Description 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.
Title wolfEngine reuses the AES-CCM nonce on TLS 1.2 / DTLS 1.2 records
Weaknesses CWE-323
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
wolfSSL
Published
Updated
Aug 28, 2026, 6:17 PM
Reserved
Aug 26, 2026, 6:08 PM
Status
Analyzed
Published
Aug 28, 2026, 4:18 PM
Modified
Sep 29, 2026, 7:10 PM