Security Resilience

CVE-2026-8720

Wolfssl 5.9.0 – 5.9.2

Published
25 June 2026
Modified
27 June 2026
Patch / advisory
CVSS Score v4 5.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0016 5th percentile
Risk Priority 30 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-2026-8720 is a medium-severity Improper Validation of Integrity Check Value (CWE-354) vulnerability in Wolfssl Wolfssl. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 5th 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 SC-13 (Cryptographic Protection) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

wc_Blake2bHmacFinal and wc_Blake2sHmacFinal discard the message when the key length exceeds the block size, producing a MAC that is independent of the input. When the supplied key is longer than the BLAKE2 block size the key-hashing branch reinitialized the running…

more

hash state, discarding the accumulated message data, so the resulting MAC depended only on the key and not on the message being authenticated. This bug is specific to the HMAC-BLAKE2 APIs that were added in wolfSSL version 5.9.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
T1016.002 Wi-Fi Discovery Discovery
Adversaries may search for information about Wi-Fi networks, such as network names and passwords, on compromised systems.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.004 SSH Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.005 VNC Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-6679Same product: Wolfssl Wolfssl
CVE-2026-55958Same product: Wolfssl Wolfssl
CVE-2026-5187Same product: Wolfssl Wolfssl
CVE-2024-1543Same product: Wolfssl Wolfssl
CVE-2026-6681Same product: Wolfssl Wolfssl
CVE-2025-7394Same product: Wolfssl Wolfssl
CVE-2026-7531Same product: Wolfssl Wolfssl
CVE-2023-6936Same product: Wolfssl Wolfssl
CVE-2025-7396Same product: Wolfssl Wolfssl
CVE-2026-55961Same product: Wolfssl Wolfssl

Affected Assets

wolfssl
wolfssl
5.9.0 — 5.9.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 10 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.4.12

Mitigating Controls (NIST 800-53 r5) AI

Requires integrity verification tools that detect unauthorized changes when checksum validation is missing or flawed.

Mandates cryptographic mechanisms that include integrity protection, preventing improper checksum validation.

Requires protection of transmitted information integrity, directly mandating correct validation of integrity checks.

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.

ID.RA-09 partial match
blocks

Mandates pre-acquisition integrity assessment, addressing only the initial portion of the weakness lifecycle.

PR.DS-01 partial match
blocks

Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data at rest.

PR.DS-02 partial match
blocks

Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data in transit.

RC.RP-03 partial match
blocks

Requires verification of backup integrity, covering validation only within recovery scenarios.

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.

removes
removes
removes
removes
removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. blocks CWE-354
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. blocks CWE-354
Oracle Linux 9 (1 rule)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. blocks CWE-354
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. blocks CWE-354
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. blocks CWE-354
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. blocks CWE-354
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. blocks CWE-354

References