Libjwt: Starting
Affects libjwtSource GCVE Database
Not known to be exploited · CVSS 5.8 Medium · fixed in 3.3.0 : update libjwt when convenient.
Data as of 13 Nov 2026, 13:11 UTC
- Patch
- Available – fixed in 3.3.0
CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:A/VC:L/VI:L/VA:H/SC:L/SI:L/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 27 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10libjwtpkg:deb/ubuntu/libjwt?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10libjwt3pkg:deb/ubuntu/libjwt3?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlibjwtpkg:deb/ubuntu/libjwt?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlibjwt3pkg:deb/ubuntu/libjwt3?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10libjwtpkg:deb/ubuntu/libjwt?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlibjwtpkg:deb/ubuntu/libjwt?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in libjwt version 3.3.0. Users should upgrade to version 3.3.0 or later. Until upgrading, users should avoid importing JWK files from untrusted sources and use the jwk2key tool to validate JWK files. Avoid using JWK files with RSA-PSS keys if possible.
Description
LibJWT versions starting from 3.0.0 up to but not including 3.3.0 have a vulnerability in the JWK parsing for RSA-PSS keys. The parser did not properly handle NULL values when expecting JSON string values, allowing specially crafted JWK files to use integers where strings were expected. This flaw could lead to denial of service or other impacts. The issue was fixed in version 3.3.0. Users are advised not to import JWK files from untrusted sources and to use the jwk2key tool to validate JWK files. Avoid using JWK files with RSA-PSS keys if possible.