# CVE-2026-81020

## Summary

- **CVE ID:** CVE-2026-81020
- **Severity:** HIGH
- **CVSS Score:** 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)
- **CWE:** CWE-323
- **Published:** Aug 28, 2026
- **Last Modified:** Aug 28, 2026

## Description

wolfEngine before 1.4.1 generates the 8-byte explicit AES-GCM nonce once when the TLS write key is set and never increments it per record. As a result every TLS 1.2 and DTLS 1.2 AES-GCM record within a connection is encrypted under an identical key and nonce pair. Reusing a GCM key and nonce discloses the keystream (the XOR of two ciphertexts equals the XOR of their plaintexts, so one known record recovers the others) and leaks the GHASH authentication key, enabling authentication tag forgery. AES-CCM, TLS 1.3, and non-TLS use of the cipher are not affected.

## Affected Products

- wolfSSL Inc. — wolfEngine (0)

## References

- [CNA](https://www.wolfssl.com/docs/security-vulnerabilities/)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.24%
- **EPSS Percentile:** 14.7

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._