CVE-2026-101918
PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.ge…
PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.
- Vendor
- pyjwt project
- Product
- pyjwt
- CVSS 3.1
- 7.5 (high), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS 3.1
- 5.3 (medium), scored by security-advisories@github.comCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CWE
- CWE-248
- Published
- 2026-09-28
- NVD modified
- 2026-10-07
- NVD status
- Analyzed
Not in the CISA KEV catalogue at the last update.
EPSS
0.36% chance of exploitation in the next 30 days (percentile 28th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- github.com (Patch)
- github.com (Product, Release Notes)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.