Vulnerability in Jpadilla Pyjwt
CVE-2026-101918
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Jpadilla Pyjwt — versions >= 2.0.0a1, < 2.15.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-101918?
- CVE-2026-101918 is a medium-severity vulnerability in Jpadilla Pyjwt, classified under CWE-248. CVSS score: 5.3/10. Published 2026-09-28.
- How severe is CVE-2026-101918?
- Medium severity. CVSS v3 base score is 5.3 out of 10.