CVE-2026-81341
Received Received - Intake

wolfEngine AES-CCM Nonce Reuse Vulnerability

Publication date: 2026-08-28

Last updated on: 2026-08-28

Assigner: wolfSSL Inc.

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-28
Last Modified
2026-08-28
Generated
2026-08-29
AI Q&A
2026-08-28
EPSS Evaluated
N/A
NVD
CVE-2026-81341
EUVD
EUVD-2026-67738

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wolfssl wolfengine to 1.4.1 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-323 Nonces should be used for the present occasion and only once.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

wolfEngine before 1.4.1 incorrectly uses a constant nonce from the input buffer instead of the TLS sequence number for AES-CCM encryption in TLS 1.2 and DTLS 1.2 records. This causes identical key-nonce pairs across all records in a connection, weakening confidentiality and integrity by allowing keystream reuse and tag forgery.

Detection Guidance

Detecting this vulnerability requires checking if wolfEngine before version 1.4.1 is in use and if AES-CCM cipher suites are enabled. Inspect your TLS/DTLS configuration for wolfEngine and verify the version. Check logs for repeated identical nonce values in AES-CCM encrypted records.

Impact Analysis

An attacker could exploit this to decrypt sensitive data or forge authentication tags, compromising secure communications. However, AES-CCM suites are not enabled by default, reducing exposure unless explicitly configured.

Compliance Impact

This vulnerability could lead to unauthorized data access or tampering, violating confidentiality and integrity requirements in GDPR and HIPAA. Organizations using vulnerable wolfEngine versions must patch to maintain compliance.

Mitigation Strategies

Upgrade wolfEngine to version 1.4.1 or later to fix the nonce handling issue. Disable AES-CCM cipher suites if not required. Ensure TLS 1.3 is used where possible as it is not affected by this vulnerability.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-81341. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart