CVE-2026-48524
LOW EPSS 12.7%
Published May 28, 20261mo ago · Modified Jun 17, 20261w ago
3.7 CVSS 3.1
Published May 28, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago
Description
PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability Low
Threat Intelligence
EPSS Exploit Probability
12.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 2
CWE-460
CWE-755
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| pyjwt_project | pyjwt | * | <2.13.0 |
References 1
- github.com https://github.com/jpadilla/pyjwt/security/advisories/GHSA-fhv5-28vv-h8m8
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.