CVE-2026-33996
MEDIUMLibJWT has NULL/bounds validation in JWK octet and RSA PSS parsing
Title source: cnaDescription
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.
Scores
CVSS v3
5.5
EPSS
0.0001
EPSS Percentile
2.5%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-476
Status
published
Products (2)
benmcollins/libjwt
>= 3.0.0, < 3.3.0
libjwt/libjwt
3.0.0 - 3.3.0
Published
Mar 27, 2026
Tracked Since
Mar 29, 2026