SEPTEMBER 18, 2026
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Case File

CVE-2026-81020

HIGH · CVSS 7.4 EPSS 0.24%

Source: NVD + CISA KEV + EPSS · Published 2026-08-28 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability affects wolfEngine versions prior to 1.4.1, where the AES-GCM nonce is generated only once per connection, leading to the reuse of the same key and nonce for all records in TLS 1.2 and DTLS 1.2. This flaw allows attackers to exploit the keystream, potentially recovering plaintext from ciphertexts and forging authentication tags. Organizations using wolfEngine for TLS 1.2 or DTLS 1.2 should prioritize patching to mitigate the risk of data exposure and authentication vulnerabilities.

CVE
CVE-2026-81020
Severity
HIGH
CVSS
7.4
EPSS
0.24%

Original NVD 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.