Vulnerability-Lookup

CVE-2026-45363 (GCVE-0-2026-45363)

Vulnerability from cvelistv5 – Published: 2026-07-14 21:32 – Updated: 2026-07-15 13:26

Title

`jwt` (Ruby gem) - empty-key HMAC bypass

Summary

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.

Severity

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-15 13:24 UTC

CWE

CWE-287 - Improper Authentication
CWE-326 - Inadequate Encryption Strength
CWE-1391 - Use of Weak Credentials

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/jwt/ruby-jwt/security/advisori…	x_refsource_CONFIRM
https://github.com/jwt/ruby-jwt/commit/9820020869…	x_refsource_MISC
https://github.com/jwt/ruby-jwt/commit/db560b769a…	x_refsource_MISC
https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3	x_refsource_MISC
https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
jwt	ruby-jwt	Affected: < 2.10.3 Affected: >= 3.0.0, < 3.2.0	guessed

Show details on NVD website

JSON

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BDU:2026-09332

Vulnerability from fstec - Published: 13.05.2026

Title

Уязвимость реализации стандарта JWT Ruby JWT, связанная с недостатками процедуры аутентификации, позволяющая нарушителю вызвать отказ в обслуживании

Description

Уязвимость реализации стандарта JWT Ruby JWT связана с недостатками процедуры аутентификации. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, вызвать отказ в обслуживании

Severity


                    
                      AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Vendor

ООО «РусБИТех-Астра», Сообщество свободного программного обеспечения

Software Name

ПК СВ «Брест», Ruby JWT

Software Version

до 4.0.2 (ПК СВ «Брест»), до 2.10.3 (Ruby JWT), от 3.0.0 до 3.2.0 (Ruby JWT)

Possible Mitigations

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года. Использование рекомендаций: Для Ruby JWT: https://github.com/advisories/GHSA-c32j-vqhx-rx3x Для ПК СВ «Брест»: обновление программного обеспечения, применение оперативного обновления ПК СВ «Брест» 4.0.2, предоставляемого в личном кабинете пользователя https://lk.astralinux.ru/ (https://wiki.astralinux.ru/x/ziLoD)

Reference

https://github.com/advisories/GHSA-c32j-vqhx-rx3x https://lk.astralinux.ru/ https://nvd.nist.gov/vuln/detail/CVE-2026-45363

CWE

CWE-287

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:H/Au:N/C:C/I:C/A:C",
  "CVSS 3.0": "AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "\u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb, \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "\u0434\u043e 4.0.2 (\u041f\u041a \u0421\u0412 \u00ab\u0411\u0440\u0435\u0441\u0442\u00bb), \u0434\u043e 2.10.3 (Ruby JWT), \u043e\u0442 3.0.0 \u0434\u043e 3.2.0 (Ruby JWT)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0412 \u0443\u0441\u043b\u043e\u0432\u0438\u044f\u0445 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0438\u044f \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u043e\u0442 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u0442\u0441\u044f \u043f\u0440\u0438\u0434\u0435\u0440\u0436\u0438\u0432\u0430\u0442\u044c\u0441\u044f \"\u0420\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u043e \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0439 \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0435 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c LINUX\", \u0438\u0437\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0445 \u0432 \u043c\u0435\u0442\u043e\u0434\u0438\u0447\u0435\u0441\u043a\u043e\u043c \u0434\u043e\u043a\u0443\u043c\u0435\u043d\u0442\u0435 \u0424\u0421\u0422\u042d\u041a \u0420\u043e\u0441\u0441\u0438\u0438, \u0443\u0442\u0432\u0435\u0440\u0436\u0434\u0451\u043d\u043d\u043e\u043c 25 \u0434\u0435\u043a\u0430\u0431\u0440\u044f 2022 \u0433\u043e\u0434\u0430.\n\n\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\n\u0414\u043b\u044f Ruby JWT:\nhttps://github.com/advisories/GHSA-c32j-vqhx-rx3x\n\n\u0414\u043b\u044f \u041f\u041a \u0421\u0412 \u00ab\u0411\u0440\u0435\u0441\u0442\u00bb:\n\u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f, \u043f\u0440\u0438\u043c\u0435\u043d\u0435\u043d\u0438\u0435 \u043e\u043f\u0435\u0440\u0430\u0442\u0438\u0432\u043d\u043e\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f \u041f\u041a \u0421\u0412 \u00ab\u0411\u0440\u0435\u0441\u0442\u00bb 4.0.2, \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u043c\u043e\u0433\u043e \u0432 \u043b\u0438\u0447\u043d\u043e\u043c \u043a\u0430\u0431\u0438\u043d\u0435\u0442\u0435 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f https://lk.astralinux.ru/ (https://wiki.astralinux.ru/x/ziLoD)",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "13.05.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "07.07.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "07.07.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-09332",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2026-45363",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u044b",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "\u041f\u041a \u0421\u0412 \u00ab\u0411\u0440\u0435\u0441\u0442\u00bb, Ruby JWT",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": null,
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u0430 JWT Ruby JWT, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u0430\u044f \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043a\u0430\u043c\u0438 \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u044b \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u0430\u044f \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u044f (CWE-287)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0440\u0435\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u0430 JWT Ruby JWT \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043a\u0430\u043c\u0438 \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u044b \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041d\u0430\u0440\u0443\u0448\u0435\u043d\u0438\u0435 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://github.com/advisories/GHSA-c32j-vqhx-rx3x\nhttps://lk.astralinux.ru/\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-45363",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u0421\u0440\u0435\u0434\u0441\u0442\u0432\u043e \u0437\u0430\u0449\u0438\u0442\u044b, \u041f\u041e \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438/\u041f\u041e \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e-\u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0433\u043e \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u0430, \u041f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e \u0437\u0430\u0449\u0438\u0442\u044b, \u041f\u0440\u0438\u043a\u043b\u0430\u0434\u043d\u043e\u0435 \u041f\u041e \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-287",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7,6)\n\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7,4)"
}

FKIE_CVE-2026-45363

Vulnerability from fkie_nvd - Published: 2026-07-14 22:16 - Updated: 2026-07-15 20:23

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964
	security-advisories@github.com	https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f
	security-advisories@github.com	https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3
	security-advisories@github.com	https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0
	security-advisories@github.com	https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "ruby-jwt",
          "vendor": "jwt",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.10.3"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.0.0, \u003c 3.2.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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, \u0027\u0027, true, algorithm: \u0027HS256\u0027) accepts an attacker-forged token because OpenSSL::HMAC.digest(\u0027SHA256\u0027, \u0027\u0027, 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."
    }
  ],
  "id": "CVE-2026-45363",
  "lastModified": "2026-07-15T20:23:47.313",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45363",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-15T13:24:12.081532Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-14T22:16:54.463",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        },
        {
          "lang": "en",
          "value": "CWE-326"
        },
        {
          "lang": "en",
          "value": "CWE-1391"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-C32J-VQHX-RX3X

Vulnerability from github – Published: 2026-05-18 17:24 – Updated: 2026-06-02 22:12

Summary

ruby-jwt: Empty-key HMAC bypass; cross-language sibling of CVE-2026-44351

Details

JWT.decode(token, '', true, algorithm: 'HS256') accepts an attacker-forged token. OpenSSL::HMAC.digest('SHA256', '', payload) returns a valid digest under an empty key, and no raise InvalidKeyError if key.empty? precondition exists in the HMAC algorithm.

JWT.decode(token, "", true, algorithm: 'HS256')
  -> JWA::Hmac.verify(verification_key: "", ...)
  -> OpenSSL::HMAC.digest('SHA256', "", signing_input) == signature

The same path is reached when a keyfinder block or key_finder: argument returns "", nil, or an array containing nil for an unknown key. JWT::Decode#find_key only rejects literal nil and empty arrays, and JWT::JWA::Hmac silently coerces nil to "" (signing_key ||= '') before signing.

JWT.decode(token, nil, true, algorithms: ['HS256']) { |_h| "" }
  -> find_key returns ""               # "" && !Array("").empty? == true
  -> JWA::Hmac.verify(verification_key: "", ...)
  -> verifies

Common application patterns that produce the unsafe value: redis.get("kid:#{kid}").to_s, ORM string columns with default: '', ENV['SECRET'] || '', Hash.new('') lookups, [primary, fallback] where fallback may be nil. Applications passing a non-empty static key:, or whose keyfinder returns nil / raises on miss, are not affected.

The existing enforce_hmac_key_length option would block this but defaults to false. On OpenSSL ≥ 3.5 the empty-key HMAC.digest call no longer raises, so the OpenSSL-3.0 rescue in JWA::Hmac#sign does not fire.

Affects HS256/HS384/HS512 via both JWT.decode (positional key and block keyfinder) and JWT::EncodedToken#verify_signature!(key_finder:)

Severity

7.4 (High)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "jwt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.2.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "jwt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.10.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45363"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1391",
      "CWE-287",
      "CWE-326"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-18T17:24:55Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "`JWT.decode(token, \u0027\u0027, true, algorithm: \u0027HS256\u0027)` accepts an attacker-forged token.\n`OpenSSL::HMAC.digest(\u0027SHA256\u0027, \u0027\u0027, payload)` returns a valid digest under an empty key, and no `raise\n  InvalidKeyError if key.empty?` precondition exists in the HMAC algorithm.\n\n```\nJWT.decode(token, \"\", true, algorithm: \u0027HS256\u0027)\n  -\u003e JWA::Hmac.verify(verification_key: \"\", ...)\n  -\u003e OpenSSL::HMAC.digest(\u0027SHA256\u0027, \"\", signing_input) == signature\n```\n\nThe same path is reached when a keyfinder block or key_finder: argument returns \"\", nil, or an\narray containing nil for an unknown key. JWT::Decode#find_key only rejects literal nil and empty\narrays, and JWT::JWA::Hmac silently coerces nil to \"\" (signing_key ||= \u0027\u0027) before signing.\n\n```\nJWT.decode(token, nil, true, algorithms: [\u0027HS256\u0027]) { |_h| \"\" }\n  -\u003e find_key returns \"\"               # \"\" \u0026\u0026 !Array(\"\").empty? == true\n  -\u003e JWA::Hmac.verify(verification_key: \"\", ...)\n  -\u003e verifies\n```\nCommon application patterns that produce the unsafe value: `redis.get(\"kid:#{kid}\").to_s`, ORM string columns with `default: \u0027\u0027`, `ENV[\u0027SECRET\u0027] || \u0027\u0027, Hash.new(\u0027\u0027)` lookups, [primary, fallback] where fallback may be nil. Applications passing a non-empty static key:, or whose keyfinder returns nil / raises on miss, are not affected.\n\nThe existing `enforce_hmac_key_length` option would block this but defaults to false. On OpenSSL \u2265 3.5 the empty-key HMAC.digest call no longer raises, so the OpenSSL-3.0 rescue in JWA::Hmac#sign does not fire.\n\nAffects HS256/HS384/HS512 via both JWT.decode (positional key and block keyfinder) and\n`JWT::EncodedToken#verify_signature!(key_finder:)`",
  "id": "GHSA-c32j-vqhx-rx3x",
  "modified": "2026-06-02T22:12:50Z",
  "published": "2026-05-18T17:24:55Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jwt/ruby-jwt/issues/724"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jwt/ruby-jwt"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/jwt/CVE-2026-45363.yml"
    },
    {
      "type": "WEB",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45363"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ruby-jwt: Empty-key HMAC bypass; cross-language sibling of CVE-2026-44351"
}

RHSA-2026:63327

Vulnerability from csaf_redhat - Published: 2026-09-03 23:02 - Updated: 2026-09-14 23:48

Summary

Red Hat Security Advisory: Satellite 6.16.13 Async Update

Severity

Important

Scope

7 vulnerabilities in this advisory, including CVE-2026-45363.

CVE-2026-45363

A flaw was found in ruby-jwt, a Ruby implementation of the RFC 7519 OAuth JSON Web Token (JWT) standard. A remote attacker can exploit this vulnerability by crafting a malicious token that is accepted due to an empty key being used in the HMAC (Hash-based Message Authentication Code) digest calculation during token verification. This allows the attacker to bypass authentication and integrity checks, potentially leading to unauthorized access or data manipulation.

7.4 (High)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Fixed: 12 products Known not affected: 102 products

https://access.redhat.com/errata/RHSA-2026:63327

Open the full advisory

RHSA-2026:63385

Vulnerability from csaf_redhat - Published: 2026-09-03 23:00 - Updated: 2026-09-15 14:13

Summary

Red Hat Security Advisory: Satellite 6.19.4 Async Update

Severity

Important

Scope

22 vulnerabilities in this advisory, including CVE-2026-45363.

CVE-2026-45363

7.4 (High)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Fixed: 6 products Known not affected: 83 products

https://access.redhat.com/errata/RHSA-2026:63385

Open the full advisory

RHSA-2026:63386

Vulnerability from csaf_redhat - Published: 2026-09-03 22:05 - Updated: 2026-09-14 23:48

Summary

Red Hat Security Advisory: Satellite 6.18.9 Async Update

Severity

Important

Scope

9 vulnerabilities in this advisory, including CVE-2026-45363.

CVE-2026-45363

7.4 (High)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Fixed: 14 products Known not affected: 51 products

https://access.redhat.com/errata/RHSA-2026:63386

Open the full advisory

RHSA-2026:63387

Vulnerability from csaf_redhat - Published: 2026-09-03 23:00 - Updated: 2026-09-14 22:08

Summary

Red Hat Security Advisory: Satellite 6.17.11 Async Update

Severity

Important

Scope

9 vulnerabilities in this advisory, including CVE-2026-45363.

CVE-2026-45363

7.4 (High)


                
                  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Fixed: 14 products Known not affected: 68 products

https://access.redhat.com/errata/RHSA-2026:63387

Open the full advisory

ubuntu-cve-2026-45363

Vulnerability from osv_ubuntu

Published

2026-07-14 22:16

Modified

2026-07-14 22:16

Summary

Details

Severity

9.1 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-45363	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-45363	REPORT
	https://github.com/jwt/ruby-jwt/commit/9820020869…	REPORT
	https://github.com/jwt/ruby-jwt/commit/db560b769a…	REPORT
	https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3	REPORT
	https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0	REPORT
	https://github.com/jwt/ruby-jwt/security/advisori…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "1.0.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@1.0.0-3?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "1.5.6-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@1.5.6-1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.6-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.1.0-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.1.0-2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.6-1",
        "2.1.0-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.2.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.2.2-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.2.2-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.7.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.7.1-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.0-2",
        "2.7.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.7.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.7.1-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.1-1"
      ]
    }
  ],
  "aliases": [],
  "details": "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, \u0027\u0027, true, algorithm: \u0027HS256\u0027) accepts an attacker-forged token because OpenSSL::HMAC.digest(\u0027SHA256\u0027, \u0027\u0027, 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.",
  "id": "UBUNTU-CVE-2026-45363",
  "modified": "2026-07-14T22:16:00Z",
  "published": "2026-07-14T22:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-45363"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45363"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-45363"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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CVE-2026-45363 (GCVE-0-2026-45363)

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature

Related by attack behaviour