{"id":"CVE-2026-45363","title":"ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard","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', '', paylo…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-287","CWE-326","CWE-1391","CWE-347"],"vendor":"jwt","product":"ruby-jwt","affected":["ruby-jwt < 2.10.3","ruby-jwt >= 3.0.0, < 3.2.0"],"published":"2026-07-14","updated":"2026-09-19","sourceUpdated":"2026-09-19T18:16:48.657","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-45363","references":[{"url":"https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964","label":"security-advisories@github.com"},{"url":"https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f","label":"security-advisories@github.com"},{"url":"https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3","label":"security-advisories@github.com"},{"url":"https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0","label":"security-advisories@github.com"},{"url":"https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x","label":"security-advisories@github.com"},{"url":"https://lists.debian.org/debian-lts-announce/2026/09/msg00022.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45363.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-45363"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2500739"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45363"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45363"},{"url":"https://access.redhat.com/errata/RHSA-2026:63327"},{"url":"https://access.redhat.com/errata/RHSA-2026:63387"},{"url":"https://access.redhat.com/errata/RHSA-2026:63386"},{"url":"https://access.redhat.com/errata/RHSA-2026:63385"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-07-15T13:24:12.081532Z"},"epss":0.00364,"epssPercentile":0.30111,"ingestedAt":"2026-09-19T19:09:10.995Z","patched":["satellite_6_16_for_rhel 8","satellite_6_16_for_rhel 9","satellite_6_17_for_rhel 9","satellite_6_18_for_rhel 9","satellite_6_19_for_rhel 9"],"scores":{"nvd":9.1,"vendor":7.4},"slug":"CVE-2026-45363","body":"## Overview\n\nruby-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:63327** · Red Hat · fixed in: Red Hat Satellite 6.16 for RHEL 8, Red Hat Satellite 6.16 for RHEL 9 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63327)\n- **RHSA-2026:63387** · Red Hat · fixed in: Red Hat Satellite 6.17 for RHEL 9 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63387)\n- **RHSA-2026:63386** · Red Hat · fixed in: Red Hat Satellite 6.18 for RHEL 9 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63386)\n- **RHSA-2026:63385** · Red Hat · fixed in: Red Hat Satellite 6.19 for RHEL 9 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63385)\n- **Red Hat VEX** · Important · affected: Red Hat 3scale API Management Platform 2, Red Hat Satellite 6 · no fix planned: Red Hat 3scale API Management Platform 2, Red Hat Satellite 6 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45363.json)","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}