CVE-2026-45363

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 84% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard. Prior to 2.10.3 and 3.2.0, JWT.decode(token, '', true, algorithm: 'HS256') accepts an attacker-forged token because OpenSSL::HMAC.digest('SHA256', '', payload) returns a valid digest under an empty key and no empty-key precondition exists in the HMAC algorithm. The same path is reached when a keyfinder block or key_finder: argument returns an empty string, nil, or an array containing nil for an unknown key, affecting HS256, HS384, and HS512 verification through JWT.decode and JWT::EncodedToken#verify_signature!. This issue is fixed in versions 2.10.3 and 3.2.0.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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 computed
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

May 18, 2026

Last Modified

July 15, 2026

Advisory Details (5)

Auto-updated Aug 1, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Empty-key HMAC bypass; cross-language sibling of CVE-2026-44351 · Advisory · jwt/ruby-jwt · GitHub

https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x
github_release Patch Available

jwt-3.2.0

Patch available: jwt/ruby-jwt v3.2.0

https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0
github_release Patch Available

jwt-2.10.3

Patch available: jwt/ruby-jwt v2.10.3

https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3
github_commit Patch Available

commit db560b769a07 (jwt/ruby-jwt)

Patch available: jwt/ruby-jwt v3.2.0 (contains commit db560b769a07)

https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f
github_commit Patch Available

commit 9820020869ad (jwt/ruby-jwt)

Patch available: jwt/ruby-jwt v2.10.3 (contains commit 9820020869ad)

https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964

Vendor Advisories for CVE-2026-45363(1)

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

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
ruby-jwt2.2.2-1 ... 3.2.0-1 (8 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
ruby-jwt2.5.0-1 ... 3.2.0-1 (6 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
ruby-jwt2.7.1-1, 3.1.2-1, 3.2.0-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
ruby-jwt2.7.1-1, 3.1.2-13.2.0-1—
RubyGems(1)
PackageVulnerable rangeFixed inDependents
jwt0.1.1 ... 2.9.3 (49 versions)2.10.3—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 44× 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. 2026-08-23 17:14 UTCEG score recompute
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:54 UTCEG score recompute
  4. 2026-08-21 23:49 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-20 19:10 UTCEG score recompute
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-17 13:51 UTCEG score recompute
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-17 10:07 UTCEG score recompute
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 03:40 UTCEG score recompute
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 01:30 UTCEG score recompute
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 02:12 UTCEG score recompute
  18. 2026-08-13 22:00 UTCEPSS rescore
  19. 2026-08-12 14:39 UTCEG score recompute
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-11 13:56 UTCEG score recompute
  22. 2026-08-11 00:42 UTCEG score recompute
  23. 2026-08-11 00:00 UTCEPSS rescore
  24. 2026-08-09 16:39 UTCEG score recompute
  25. 2026-08-09 13:46 UTCEPSS rescore
Show 36 more
  1. 2026-08-09 01:40 UTCEG score recompute
  2. 2026-08-08 16:37 UTCEPSS rescore
  3. 2026-08-07 17:51 UTCEG score recompute
  4. 2026-08-05 21:25 UTCEG score recompute
  5. 2026-08-05 19:17 UTCEPSS rescore
  6. 2026-08-04 15:10 UTCEPSS rescore
  7. 2026-08-04 10:38 UTCEPSS rescore
  8. 2026-08-03 17:05 UTCEG score recompute
  9. 2026-08-03 10:36 UTCEPSS rescore
  10. 2026-08-02 05:53 UTCEG score recompute
  11. 2026-08-02 02:27 UTCEPSS rescore
  12. 2026-08-01 18:29 UTCEG score recompute
  13. 2026-08-01 04:16 UTCEPSS rescore
  14. 2026-07-30 16:28 UTCEPSS rescore
  15. 2026-07-30 01:30 UTCEPSS rescore
  16. 2026-07-28 15:36 UTCEPSS rescore
  17. 2026-07-27 14:13 UTCEPSS rescore
  18. 2026-07-26 14:54 UTCEPSS rescore
  19. 2026-07-26 14:54 UTCEPSS rescore
  20. 2026-07-25 14:18 UTCEPSS rescore
  21. 2026-07-24 14:17 UTCEPSS rescore
  22. 2026-07-23 14:18 UTCEPSS rescore
  23. 2026-07-23 03:16 UTCEG score recompute▲ 1.70
  24. 2026-07-22 14:08 UTCEPSS rescore
  25. 2026-07-21 15:24 UTCEPSS rescore
  26. 2026-07-20 17:08 UTCEPSS rescore
  27. 2026-07-19 02:29 UTCEPSS rescore
  28. 2026-07-18 10:04 UTCEPSS rescore
  29. 2026-07-18 00:29 UTCOSV refresh
  30. 2026-07-16 17:03 UTCEPSS rescore
  31. 2026-07-15 16:57 UTCEPSS rescore
  32. 2026-07-14 21:35 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  33. 2026-06-14 23:18 UTCEPSS rescore
  34. 2026-06-13 23:00 UTCEPSS rescore
  35. 2026-06-12 23:12 UTCEPSS rescore
  36. 2026-05-24 06:16 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-45363?
CVE-2026-45363 is a critical vulnerability published on May 18, 2026. ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard. Prior to 2.10.3 and 3.2.0, JWT.decode(token, '', true, algorithm: 'HS256') accepts an attacker-forged token because OpenSSL::HMAC.digest('SHA256', '', payload) returns a valid digest under an empty key and no empty-key…
When was CVE-2026-45363 disclosed?
CVE-2026-45363 was first published in the National Vulnerability Database on May 18, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45363 actively exploited?
CVE-2026-45363 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.1% of all scored CVEs.
What is the CVSS score of CVE-2026-45363?
CVE-2026-45363 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-45363?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45363, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-45363

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