{"id":"CVE-2026-33996","aliases":["DEBIAN-CVE-2026-33996","EUVD-2026-16899","GHSA-ph96-hqpc-9f66","UBUNTU-CVE-2026-33996"],"status":"published","title":"LibJWT has NULL/bounds validation in JWK octet and RSA PSS parsing","description":"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.","severity":{"version":"4.0","score":5.8,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00158,"percentile":0.04961,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-476"],"published":"2026-03-27T22:21:21Z","modified":"2026-10-28T10:55:04Z","fixes":[{"ecosystem":"Debian:14","package":"libjwt3","fixed_in":["3.3.2-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:14","package":"libjwt3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.3.2-1"}]}],"versions":["3.2.2-1","3.2.3-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"libjwt","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"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1","1.10.2-1build1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.2-1build1","1.17.0-2","1.17.0-2build1","1.17.0-2build2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.2-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.2-1build1","1.17.2-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"libjwt3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.3-1","3.3.3-1","3.3.3-1build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"libjwt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.2-1","1.17.2-1build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"libjwt3","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.2-1","3.2.3-1"]}],"products":[{"vendor":"benmcollins","product":"libjwt"},{"vendor":"libjwt","product":"libjwt"}],"references":[{"url":"https://github.com/benmcollins/libjwt/security/advisories/GHSA-ph96-hqpc-9f66","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","report"]},{"url":"https://github.com/benmcollins/libjwt/commit/cfd890286fa49ae61b534c937c9f0428b5c6034c","tags":["x_refsource_MISC","Patch","fix","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33996.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33996","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-33996","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-33996","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-33996","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-33996","title":"LibJWT has NULL/bounds validation in JWK octet and RSA PSS parsing","description":"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.","status":"published","published":"2026-03-27T22:21:21.465Z","modified":"2026-03-31T18:53:51.741Z","cvss":[{"version":"4.0","score":5.8,"vector":"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","level":"medium","assessor":"cna"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:20:07.609948Z"}],"euvd":[{"id":"EUVD-2026-16899","description":"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.","status":"published","published":"2026-03-27T22:21:21Z","modified":"2026-03-31T18:53:51Z","cvss":[{"version":"4.0","score":5.8,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T19:25:24.891983Z"}],"nvd":[{"id":"CVE-2026-33996","description":"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.","status":"published","published":"2026-03-27T23:17:14.59Z","modified":"2026-06-17T10:38:24.333Z","cvss":[{"version":"4.0","score":5.8,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:12:11.678711Z"}],"osv":[{"id":"CVE-2026-33996","title":"LibJWT has NULL/bounds validation in JWK octet and RSA PSS parsing","description":"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.","status":"published","published":"2026-03-27T22:21:21.465Z","modified":"2026-10-28T10:55:04.178748046Z","cvss":[{"version":"4.0","score":5.8,"vector":"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","level":"medium"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T15:45:02.247031Z"},{"id":"DEBIAN-CVE-2026-33996","description":"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.","status":"published","published":"2026-03-27T23:17:14.59Z","modified":"2026-10-01T03:03:22.512000091Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"UBUNTU-CVE-2026-33996","description":"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.","status":"published","published":"2026-03-27T23:17:00Z","modified":"2026-10-17T12:58:11.09721103Z","cvss":[{"version":"4.0","score":5.8,"vector":"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","level":"medium"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T16:56:16.036833Z"}]}}