Cyber Resilience

CVE-2026-8720

Medium

Published: 25 June 2026

Published
25 June 2026
Modified
27 June 2026
KEV Added
Patch
CVSS Score v4 5.9 CVSS: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 0.0011 1.6th percentile
Risk Priority 35 floored blend · peak EPSS

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, ranked at the 1.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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 TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-7396Same product: Wolfssl Wolfssl
CVE-2024-1544Same product: Wolfssl Wolfssl
CVE-2026-6331Same product: Wolfssl Wolfssl
CVE-2026-6450Same product: Wolfssl Wolfssl
CVE-2026-5503Same product: Wolfssl Wolfssl
CVE-2021-3336Same product: Wolfssl Wolfssl
CVE-2026-55960Same product: Wolfssl Wolfssl
CVE-2025-7394Same product: Wolfssl Wolfssl
CVE-2026-7532Same product: Wolfssl Wolfssl
CVE-2022-34293Same product: Wolfssl Wolfssl

Affected Assets

wolfssl
wolfssl
5.9.0 — 5.9.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-354

Proper validation of integrity check values is required for reliable tamper detection, directly reducing undetected modification risks.

addresses: CWE-354

Requires validation of integrity check values on every resolution response, directly mitigating tampered or corrupted DNS data.

addresses: CWE-354

Control mandates proper validation of integrity values (checksums) on prepared data, making flawed validation of those checks ineffective for attackers.

addresses: CWE-354

Requires use of proper integrity verification tools, reducing the chance an incorrect check value is accepted.

addresses: CWE-354

Requires proper validation of integrity mechanisms, directly mitigating flawed check-value handling.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

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. via 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. via CWE-354
Oracle Linux 9 (1 rule)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. via 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. via 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. via 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. via 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. via CWE-354

References