{"id":"UBUNTU-CVE-2026-33996","details":"LibJWT is a C JSON Web Token Library. Starting in version 3.0.0 and prior to version 3.3.0, the JWK parsing for RSA-PSS did not protect against a NULL value when expecting to parse JSON string values. A specially crafted JWK file could exploit this behavior by using integers in places where the code expected a string. This was fixed in v3.3.0. A workaround is available. Users importing keys through a JWK file should not do so from untrusted sources. Use the `jwk2key` tool to check for validity of a JWK file. Likewise, if possible, do not use JWK files with RSA-PSS keys.","modified":"2026-05-20T16:25:31.867351893Z","published":"2026-03-27T23:17:00Z","upstream":["CVE-2026-33996"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33996"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33996"},{"type":"REPORT","url":"https://github.com/benmcollins/libjwt/security/advisories/GHSA-ph96-hqpc-9f66"},{"type":"REPORT","url":"https://github.com/benmcollins/libjwt/commit/cfd890286fa49ae61b534c937c9f0428b5c6034c"}],"affected":[{"package":{"name":"libjwt","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.0+dfsg-1","1.8.0+dfsg-2","1.9.0-1","1.9.0-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.9.0-1build1","binary_name":"libjwt0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjwt-gnutls0","binary_version":"1.10.2-1"},{"binary_name":"libjwt0","binary_version":"1.10.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1","1.10.2-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjwt-gnutls0","binary_version":"1.10.2-1build1"},{"binary_name":"libjwt0","binary_version":"1.10.2-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1build1","1.17.0-2","1.17.0-2build1","1.17.0-2build2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.17.0-2build2","binary_name":"libjwt-gnutls2"},{"binary_name":"libjwt2","binary_version":"1.17.0-2build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.17.2-1","binary_name":"libjwt-gnutls2"},{"binary_version":"1.17.2-1","binary_name":"libjwt2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libjwt?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.2-1","1.17.2-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libjwt-gnutls2","binary_version":"1.17.2-1build1"},{"binary_version":"1.17.2-1build1","binary_name":"libjwt2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}},{"package":{"name":"libjwt3","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libjwt3?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.2-1","3.2.3-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.3-1","binary_name":"jwt-tools"},{"binary_name":"libjwt14","binary_version":"3.2.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33996.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:A/VC:L/VI:L/VA:H/SC:L/SI:L/SA:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}