CVE-2026-33996: Libjwt

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Libjwt Libjwt: from 3.0.0, before 3.3.0 (fixed in 3.3.0)

Published 2026-03-27. Last modified 2026-06-17.