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.
CVE-2026-6331
Score 7.5 from GitHub Security Advisory (severity: LOW) published 2026-06-26. NVD baseline CVSS 7.5; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 38(Track)EG Risk 38/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 9%
- KEV
- Not listed
Published
June 25, 2026
Last Modified
June 27, 2026
Advisory Details (2)
Auto-updated Jun 27, 2026wolfSSL Security Vulnerabilities | Documentation - wolfSSL
https://www.wolfssl.com/docs/security-vulnerabilities/Various fixes
Fix merged in wolfSSL/wolfssl PR #10192 on 2026-04-15 — awaiting tagged release
https://github.com/wolfSSL/wolfssl/pull/10192Vendor Advisories for CVE-2026-6331(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(3 across 3 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| wolfssl | 4.6.0+p1-0+deb11u1 ... 5.9.2-1 (40 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| wolfssl | 5.5.4-2, 5.5.4-2+deb12u1, 5.5.4-2+deb12u2 | 5.5.4-2+deb12u3 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| wolfssl | 5.7.2-0.1 ... 5.9.2-1 (14 versions) | — | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 21× in last 7d / 103× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 192 total refreshes for this CVE.
- 2026-08-26 14:47 UTCEPSS rescore
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-25 01:59 UTCEG score recompute
- 2026-08-25 01:58 UTCGHSA enrichment
- 2026-08-24 13:13 UTCEG score recompute
- 2026-08-24 13:13 UTCGHSA enrichment
- 2026-08-24 00:27 UTCGHSA enrichment
- 2026-08-23 11:41 UTCEG score recompute
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- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-22 22:56 UTCGHSA enrichment
- 2026-08-22 10:10 UTCEG score recompute
- 2026-08-22 10:10 UTCGHSA enrichment
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 21:18 UTCGHSA enrichment
- 2026-08-21 08:32 UTCEG score recompute
- 2026-08-21 08:32 UTCGHSA enrichment
- 2026-08-20 22:56 UTCEPSS rescore
- 2026-08-20 19:46 UTCGHSA enrichment
- 2026-08-20 07:00 UTCEG score recompute
- 2026-08-20 07:00 UTCGHSA enrichment
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 14:11 UTCGHSA enrichment
- 2026-08-19 01:12 UTCEG score recompute
- 2026-08-19 01:12 UTCGHSA enrichment
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- 2026-08-18 13:49 UTCEPSS rescore
- 2026-08-18 13:49 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 11:49 UTCGHSA enrichment
- 2026-08-16 23:01 UTCEG score recompute
- 2026-08-16 23:01 UTCGHSA enrichment
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 10:15 UTCEG score recompute
- 2026-08-16 10:15 UTCGHSA enrichment
- 2026-08-16 02:15 UTCEPSS rescore
- 2026-08-15 21:30 UTCGHSA enrichment
- 2026-08-15 08:44 UTCEG score recompute
- 2026-08-15 08:44 UTCGHSA enrichment
- 2026-08-15 01:31 UTCEPSS rescore
- 2026-08-14 19:58 UTCGHSA enrichment
- 2026-08-14 07:13 UTCEG score recompute
- 2026-08-14 07:13 UTCGHSA enrichment
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 18:27 UTCGHSA enrichment
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- 2026-08-12 14:57 UTCEG score recompute
- 2026-08-12 14:57 UTCGHSA enrichment
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-12 02:12 UTCEG score recompute
- 2026-08-12 02:12 UTCGHSA enrichment
- 2026-08-11 13:26 UTCGHSA enrichment
- 2026-08-11 00:36 UTCEG score recompute
- 2026-08-11 00:36 UTCGHSA enrichment
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 11:50 UTCGHSA enrichment
- 2026-08-09 23:05 UTCEG score recompute
- 2026-08-09 23:05 UTCGHSA enrichment
- 2026-08-09 13:47 UTCEPSS rescore
- 2026-08-09 10:19 UTCGHSA enrichment
- 2026-08-08 21:34 UTCGHSA enrichment
- 2026-08-08 08:48 UTCGHSA enrichment
- 2026-08-07 20:03 UTCGHSA enrichment
- 2026-08-07 07:17 UTCGHSA enrichment
- 2026-08-06 18:31 UTCEG score recompute
- 2026-08-06 18:31 UTCGHSA enrichment
- 2026-08-06 13:47 UTCEPSS rescore
- 2026-08-06 05:46 UTCEG score recompute
- 2026-08-06 05:46 UTCGHSA enrichment
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 17:00 UTCGHSA enrichment
- 2026-08-05 03:49 UTCEG score recompute
- 2026-08-05 03:49 UTCGHSA enrichment
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 15:02 UTCEG score recompute
- 2026-08-04 15:02 UTCGHSA enrichment
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-03 20:41 UTCEG score recompute
- 2026-08-03 20:41 UTCGHSA enrichment
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-03 07:54 UTCGHSA enrichment
- 2026-08-02 19:09 UTCGHSA enrichment
- 2026-08-02 06:23 UTCEG score recompute
- 2026-08-02 06:23 UTCGHSA enrichment
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 17:18 UTCGHSA enrichment
- 2026-08-01 04:32 UTCEG score recompute
- 2026-08-01 04:31 UTCGHSA enrichment
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-31 15:43 UTCGHSA enrichment
- 2026-07-31 02:46 UTCEG score recompute
- 2026-07-31 02:46 UTCGHSA enrichment
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 13:43 UTCEG score recompute
- 2026-07-30 13:43 UTCGHSA enrichment
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-30 00:36 UTCGHSA enrichment
- 2026-07-29 09:39 UTCGHSA enrichment
- 2026-07-28 20:53 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-347
Frequently asked(5)
What is CVE-2026-6331?
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What is the CVSS score of CVE-2026-6331?
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Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-6331
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