Security Resilience

CVE-2026-81020

Wolfssl Wolfengine ≤ 1.4.1

Published
28 August 2026
Modified
29 September 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0038 31th percentile
Risk Priority 55 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-81020 is a high-severity Reusing a Nonce, Key Pair in Encryption (CWE-323) vulnerability in Wolfssl Wolfengine. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked at the 31th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-323

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-81341Same product: Wolfssl Wolfengine
CVE-2026-55967Same vendor: Wolfssl
CVE-2026-81019Same vendor: Wolfssl
CVE-2024-41951Shared CWE-323
CVE-2026-50577Shared CWE-323
CVE-2024-36289Shared CWE-323
CVE-2026-56369Shared CWE-323
CVE-2024-21530Shared CWE-323
CVE-2026-59099Shared CWE-323
CVE-2026-3099Shared CWE-323

Affected Assets

wolfssl
wolfengine
≤ 1.4.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.8.3
  • V11.3.4

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover nonce reuse through static analysis, fuzzing, or known-answer tests.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles include correct use of cryptographic primitives such as unique nonces per key.

SC-13 Cryptographic Protection partial match

Selecting and implementing appropriate cryptographic algorithms and modes reduces nonce-reuse exposure.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent nonce/key reuse errors in cryptographic implementations.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.19 Installation of software on operational systems partial match
removes
A.8.24 Use of cryptography partial match
blocks

Mandates proper cryptographic key and nonce management, directly preventing nonce/key-pair reuse.

A.8.26 Application security requirements partial match
removes
A.8.27 Secure system architecture and engineering principles partial match
removes
A.8.28 Secure coding partial match
prevents

Secure-coding rules can require unique nonces, but the control is broader than this single weakness.

A.8.29 Security testing in development and acceptance partial match
finds

Security testing can detect nonce reuse, yet the control addresses many other issues beyond this CWE.

References