CVE-2026-33996
Publication date 27 March 2026
Last updated 10 July 2026
Ubuntu priority
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
| Package | Ubuntu Release | Status |
|---|---|---|
| libjwt | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| libjwt3 | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release |
Severity score breakdown
CVSS version:
Base score
5.8 · Medium
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
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