NULL pointer dereference in Benmcollins Libjwt
CVE-2026-33996
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (6.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Benmcollins Libjwt — versions >= 3.0.0, < 3.3.0
- Libjwt
Weakness classification (CWE)
References
- github.com/benmcollins/libjwt/security/advisories/GHSA-ph96-hqpc-9f66 (Mitigation, Vendor Advisory)
- github.com/benmcollins/libjwt/commit/cfd890286fa49ae61b534c937c9f0428b5c6034c (Patch)
Frequently asked questions
- What is CVE-2026-33996?
- CVE-2026-33996 is a medium-severity vulnerability in Benmcollins Libjwt, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-03-27.
- How severe is CVE-2026-33996?
- Medium severity. CVSS v3 base score is 5.5 out of 10.