CVE catalog

CVE-2026-6331

Severity: Low · CVSS 2.1
Published: Jun 25, 2026, 10:17:03 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.19% · Oct 25, 2026

HMAC zero-length tag forgery in EVP_DigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility HMAC verify path the supplied signature length was only checked as not exceeding the MAC length, so a zero-length or otherwise truncated tag could pass verification. The fix requires the supplied tag length to exactly equal the MAC length and rejects a zero-length MAC, so a forged short or empty tag is no longer accepted.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	wolfssl	sid	`5.9.2-1.2`	fixed
Debian	wolfssl	trixie	`5.7.2-0.1+deb13u2`	fixed
Debian	wolfssl	bookworm	`5.5.4-2+deb12u2`	vulnerable
Debian	wolfssl	bookworm-security	`5.5.4-2+deb12u3`	fixed
Cpe	wolfssl	Not reported	Not reported	vulnerable
Cpe	wolfssl	Not reported	`5.9.2`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	wolfssl	source	sid	`5.9.2-1`	not yet assigned	Not reported	[1140815]
Debian	wolfssl	source	trixie	`5.7.2-0.1+deb13u2`	not yet assigned	Not reported	[1140815]
Debian	wolfssl	source	bookworm	`5.5.4-2+deb12u3`	not yet assigned	Not reported	[1140815]
Cpe	wolfssl	cpe	Not reported	`5.9.2`	Not reported	Not reported	Not reported

[Debian bug #1140815]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libwolfssl35]Affected
Source package: [wolfssl]
Details (4)
- 5.5.4-2+deb12u2 · amd64 · bookworm
  Affected · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u2 · arm64 · bookworm
  Affected · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · amd64 · bookworm-security
  Fixed · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · arm64 · bookworm-security
  Fixed · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
[libwolfssl-dev]Affected
Source package: [wolfssl]
Details (4)
- 5.5.4-2+deb12u2 · amd64 · bookworm
  Affected · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u2 · arm64 · bookworm
  Affected · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · amd64 · bookworm-security
  Fixed · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12
- 5.5.4-2+deb12u3 · arm64 · bookworm-security
  Fixed · Fixed: 5.5.4-2+deb12u3
  nvd · wolfssl · debian · bookworm; nvd · wolfssl · debian · 12

[Debian 13 (Trixie)]

[libwolfssl42t64]Affected
Source package: [wolfssl]
Details (2)
- 5.7.2-0.1+deb13u1 · amd64 · trixie
  Affected · Fixed: 5.7.2-0.1+deb13u2
  nvd · wolfssl · debian · 13
- 5.7.2-0.1+deb13u1 · arm64 · trixie
  Affected · Fixed: 5.7.2-0.1+deb13u2
  nvd · wolfssl · debian · 13
[libwolfssl-dev]Affected
Source package: [wolfssl]
Details (2)
- 5.7.2-0.1+deb13u1 · amd64 · trixie
  Affected · Fixed: 5.7.2-0.1+deb13u2
  nvd · wolfssl · debian · 13
- 5.7.2-0.1+deb13u1 · arm64 · trixie
  Affected · Fixed: 5.7.2-0.1+deb13u2
  nvd · wolfssl · debian · 13

Observed: Oct 23, 2026, 9:45:23 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database]