CVE-2026-12340

HIGHNVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory published 2026-06-25. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65 bytes results in an out-of-bounds heap read, leading to a potential crash (denial of service); there is no out-of-bounds write. Note this only affects builds with SM2 support (--enable-sm2 or --enable-all).

CVSS v3
7.5
EG Score
7.5(high)
EPSS
13.3%
KEV
Not listed

Published

June 25, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 26, 2026
Patch available. Sources: github_pr.
generic Patch Available

wolfSSL Security Vulnerabilities | Documentation - wolfSSL

https://www.wolfssl.com/docs/security-vulnerabilities/
github_pr

Fixes for SM2/3 and FindMultiAttrib

Fix merged in wolfSSL/wolfssl PR #10641 on 2026-06-10 — awaiting tagged release

https://github.com/wolfSSL/wolfssl/pull/10641

Vendor Advisories for CVE-2026-12340(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 34× in last 7d / 55× 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.

  1. 2026-07-06 18:37 UTCEG score recompute
  2. 2026-07-06 18:37 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 05:45 UTCEG score recompute
  5. 2026-07-06 05:45 UTCGHSA enrichment
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 16:55 UTCEG score recompute
  8. 2026-07-05 16:55 UTCGHSA enrichment
  9. 2026-07-05 04:07 UTCEG score recompute
  10. 2026-07-05 04:07 UTCGHSA enrichment
  11. 2026-07-05 02:30 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 15:19 UTCEG score recompute
  14. 2026-07-04 15:19 UTCGHSA enrichment
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-04 02:30 UTCEG score recompute
  17. 2026-07-04 02:30 UTCGHSA enrichment
  18. 2026-07-03 13:38 UTCEG score recompute
  19. 2026-07-03 13:38 UTCGHSA enrichment
  20. 2026-07-03 00:50 UTCEG score recompute
  21. 2026-07-03 00:50 UTCGHSA enrichment
  22. 2026-07-02 12:02 UTCEG score recompute
  23. 2026-07-02 12:02 UTCGHSA enrichment
  24. 2026-07-01 23:13 UTCEG score recompute
  25. 2026-07-01 23:13 UTCGHSA enrichment
Show 30 more
  1. 2026-07-01 15:06 UTCEPSS rescore
  2. 2026-07-01 15:06 UTCEPSS rescore
  3. 2026-07-01 10:25 UTCEG score recompute
  4. 2026-07-01 10:25 UTCGHSA enrichment
  5. 2026-06-30 23:22 UTCEPSS rescore
  6. 2026-06-30 21:37 UTCEG score recompute
  7. 2026-06-30 21:36 UTCGHSA enrichment
  8. 2026-06-30 08:46 UTCEG score recompute
  9. 2026-06-30 08:46 UTCGHSA enrichment
  10. 2026-06-29 19:58 UTCEG score recompute
  11. 2026-06-29 19:58 UTCGHSA enrichment
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 07:10 UTCEG score recompute
  14. 2026-06-29 07:09 UTCGHSA enrichment
  15. 2026-06-28 18:20 UTCEG score recompute
  16. 2026-06-28 18:20 UTCGHSA enrichment
  17. 2026-06-28 14:07 UTCEPSS rescore
  18. 2026-06-28 05:31 UTCEG score recompute
  19. 2026-06-28 05:31 UTCGHSA enrichment
  20. 2026-06-28 04:56 UTCEPSS rescore
  21. 2026-06-28 04:56 UTCEPSS rescore
  22. 2026-06-27 16:43 UTCEG score recompute▲ 1.20
  23. 2026-06-27 16:43 UTCGHSA enrichment
  24. 2026-06-27 03:08 UTCEPSS rescore
  25. 2026-06-26 19:41 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  26. 2026-06-26 15:45 UTCEG score recompute▲ 6.30
  27. 2026-06-26 15:45 UTCGHSA enrichment
  28. 2026-06-26 15:40 UTCNVD updateCVSS v3 → 6.3 · CVSS v4 → 6.3
  29. 2026-06-25 21:46 UTCEG score recompute
  30. 2026-06-25 21:46 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-12340?
CVE-2026-12340 is a high vulnerability published on June 25, 2026. Out-of-bounds heap read during SM2/SM3 certificate signature verification. When parsing a certificate with an SM3wSM2 signature, the Subject Key Identifier computation reads the trailing 65 bytes of the public key without checking that the key is at least that long. A public key shorter than 65…
When was CVE-2026-12340 disclosed?
CVE-2026-12340 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12340 actively exploited?
CVE-2026-12340 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12340?
CVE-2026-12340 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-12340?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12340, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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