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: 0.4%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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%
EPSS PROB
0.4%
EPSS %ILE
28th
KEV
Not listed

Published

May 18, 2026

Last Modified

September 19, 2026

Advisory Details (5)

Auto-updated Sep 16, 2026
Patch available. Sources: github, github_commit, github_release.
githubMentions a patch (unverified)

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(5)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrubygem-jwt-0:2.10.3-1.el9sat2026-09-03redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-jwt2.2.2-1 ... 3.2.0-1 (8 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-jwt2.5.0-1
  • every version up to 2.5.0-1+deb12u1: fixed in 2.5.0-1+deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-jwt2.7.1-1, 3.1.2-1, 3.2.0-1, 3.3.0-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
ruby-jwt2.7.1-1, 3.1.2-1
  • every version up to 3.2.0-1: fixed in 3.2.0-1
—
RubyGems(1)
PackageVulnerable rangeFix by version rangeDependents
jwt0.1.1 ... 2.9.3 (49 versions)
  • 3.0.0 up to 3.2.0: fixed in 3.2.0
  • every version up to 2.10.3: fixed in 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 / 28× 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 101 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-09 10:58 UTCOSV refresh
  3. 2026-10-08 17:12 UTCEPSS rescore
  4. 2026-10-07 23:48 UTCEPSS rescore
  5. 2026-10-06 15:18 UTCEPSS rescore
  6. 2026-10-05 17:43 UTCEPSS rescore
  7. 2026-10-04 23:22 UTCEPSS rescore
  8. 2026-10-03 14:25 UTCEPSS rescore
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-27 13:48 UTCEPSS rescore
  12. 2026-09-26 15:58 UTCEPSS rescore
  13. 2026-09-23 17:53 UTCEPSS rescore
  14. 2026-09-20 20:15 UTCEPSS rescore
  15. 2026-09-19 18:23 UTCEG score recompute
  16. 2026-09-19 18:23 UTCVendor advisory
  17. 2026-09-19 18:15 UTCEG score recompute
  18. 2026-09-19 18:15 UTCVendor advisory
  19. 2026-09-18 19:28 UTCEPSS rescore
  20. 2026-09-17 19:31 UTCEPSS rescore
  21. 2026-09-16 14:08 UTCEPSS rescore
  22. 2026-09-16 05:15 UTCEPSS rescore
  23. 2026-09-13 16:47 UTCEPSS rescore
  24. 2026-09-12 15:01 UTCEPSS rescore
  25. 2026-09-11 20:40 UTCOSV refresh
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  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 09:37 UTCEPSS rescore
  3. 2026-09-10 09:34 UTCEPSS rescore
  4. 2026-09-08 22:00 UTCEPSS rescore
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-06 13:47 UTCEPSS rescore
  7. 2026-09-04 05:06 UTCEPSS rescore
  8. 2026-09-02 14:12 UTCEPSS rescore
  9. 2026-09-01 13:54 UTCEPSS rescore
  10. 2026-08-30 19:17 UTCEPSS rescore
  11. 2026-08-30 01:22 UTCEPSS rescore
  12. 2026-08-28 21:41 UTCEPSS rescore
  13. 2026-08-27 14:25 UTCEPSS rescore
  14. 2026-08-26 14:46 UTCEPSS rescore
  15. 2026-08-25 13:49 UTCEPSS rescore
  16. 2026-08-23 17:14 UTCEG score recompute
  17. 2026-08-23 00:19 UTCEPSS rescore
  18. 2026-08-21 23:54 UTCEG score recompute
  19. 2026-08-21 23:49 UTCEPSS rescore
  20. 2026-08-20 22:55 UTCEPSS rescore
  21. 2026-08-20 19:10 UTCEG score recompute
  22. 2026-08-19 17:04 UTCEPSS rescore
  23. 2026-08-18 13:48 UTCEPSS rescore
  24. 2026-08-17 13:51 UTCEG score recompute
  25. 2026-08-17 13:47 UTCEPSS rescore
  26. 2026-08-17 10:07 UTCEG score recompute
  27. 2026-08-16 14:56 UTCEPSS rescore
  28. 2026-08-16 03:40 UTCEG score recompute
  29. 2026-08-16 02:14 UTCEPSS rescore
  30. 2026-08-15 01:30 UTCEG score recompute
  31. 2026-08-15 01:30 UTCEPSS rescore
  32. 2026-08-14 02:12 UTCEG score recompute
  33. 2026-08-13 22:00 UTCEPSS rescore
  34. 2026-08-12 14:39 UTCEG score recompute
  35. 2026-08-12 13:51 UTCEPSS rescore
  36. 2026-08-11 13:56 UTCEG score recompute
  37. 2026-08-11 00:42 UTCEG score recompute
  38. 2026-08-11 00:00 UTCEPSS rescore
  39. 2026-08-09 16:39 UTCEG score recompute
  40. 2026-08-09 13:46 UTCEPSS rescore
  41. 2026-08-09 01:40 UTCEG score recompute
  42. 2026-08-08 16:37 UTCEPSS rescore
  43. 2026-08-07 17:51 UTCEG score recompute
  44. 2026-08-05 21:25 UTCEG score recompute
  45. 2026-08-05 19:17 UTCEPSS rescore
  46. 2026-08-04 15:10 UTCEPSS rescore
  47. 2026-08-04 10:38 UTCEPSS rescore
  48. 2026-08-03 17:05 UTCEG score recompute
  49. 2026-08-03 10:36 UTCEPSS rescore
  50. 2026-08-02 05:53 UTCEG score recompute
  51. 2026-08-02 02:27 UTCEPSS rescore
  52. 2026-08-01 18:29 UTCEG score recompute
  53. 2026-08-01 04:16 UTCEPSS rescore
  54. 2026-07-30 16:28 UTCEPSS rescore
  55. 2026-07-30 01:30 UTCEPSS rescore
  56. 2026-07-28 15:36 UTCEPSS rescore
  57. 2026-07-27 14:13 UTCEPSS rescore
  58. 2026-07-26 14:54 UTCEPSS rescore
  59. 2026-07-26 14:54 UTCEPSS rescore
  60. 2026-07-25 14:18 UTCEPSS rescore
  61. 2026-07-24 14:17 UTCEPSS rescore
  62. 2026-07-23 14:18 UTCEPSS rescore
  63. 2026-07-23 03:16 UTCEG score recompute▲ 1.70
  64. 2026-07-22 14:08 UTCEPSS rescore
  65. 2026-07-21 15:24 UTCEPSS rescore
  66. 2026-07-20 17:08 UTCEPSS rescore
  67. 2026-07-19 02:29 UTCEPSS rescore
  68. 2026-07-18 10:04 UTCEPSS rescore
  69. 2026-07-18 00:29 UTCOSV refresh
  70. 2026-07-16 17:03 UTCEPSS rescore
  71. 2026-07-15 16:57 UTCEPSS rescore
  72. 2026-07-14 21:35 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  73. 2026-06-14 23:18 UTCEPSS rescore
  74. 2026-06-13 23:00 UTCEPSS rescore
  75. 2026-06-12 23:12 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Same product

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Debian:11:ruby-jwt

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 on May 18, 2026, with the most recent update on September 19, 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 0.4% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-45363?
CVE-2026-45363 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-45363?
A fix for CVE-2026-45363 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-45363 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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