wolfEngine reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record (CVE-2026-81020) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-81020

wolfEngine reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record

Answer in brief

CVE-2026-81020 records a Unknown severity vulnerability in wolfEngine reuses the AES-GCM nonce on every TLS 1.2 / DTLS 1.2 record. The current sources do not mark it as known exploited. The current feed maps wolfSSL Inc./wolfEngine (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 28, 2026Updated Aug 28, 2026Source checked Aug 28, 2026First seen by HOL Aug 28, 2026Material review Aug 28, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps wolfSSL Inc./wolfEngine (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
wolfSSL Inc./wolfEnginegeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for wolfSSL Inc./wolfEngine.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 28, 2026

Sources and claim methodology

Source referencewolfssl.com

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.