CVE-2026-33996

MEDIUM EPSS 4.6%
Published Mar 27, 20263mo ago · Modified Jun 17, 20261w ago
5.8 CVSS 4.0
Medium
Find Similar
Published Mar 27, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
5.8
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Adjacent
Attack Complexity High
Privileges Required None
User Interaction A
Scope X

Threat Intelligence

EPSS Exploit Probability
4.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 1

VendorProductVersionRange
libjwtlibjwt*≥3.0.0  –  <3.3.0

References 2

  • github.com https://github.com/benmcollins/libjwt/commit/cfd890286fa49ae61b534c937c9f0428b5c6034c
    Patch
  • github.com https://github.com/benmcollins/libjwt/security/advisories/GHSA-ph96-hqpc-9f66
    MitigationVendor Advisory

Remediation

  • github.com https://github.com/benmcollins/libjwt/commit/cfd890286fa49ae61b534c937c9f0428b5c6034c
    Patch