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.
Metrics
Affected Vendors & Products
References
History
Wed, 07 Oct 2026 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Pyjwt Project
Pyjwt Project pyjwt |
|
| CPEs | cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Pyjwt Project
Pyjwt Project pyjwt |
Tue, 29 Sep 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 29 Sep 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
threat_severity
|
Mon, 28 Sep 2026 23:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Jpadilla
Jpadilla pyjwt |
|
| Vendors & Products |
Jpadilla
Jpadilla pyjwt |
Mon, 28 Sep 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False) | |
| Weaknesses | CWE-248 | |
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-09-28T20:11:55.278Z
Updated: 2026-09-29T13:57:29.516Z
Reserved: 2026-09-28T15:55:37.908Z
Link: CVE-2026-101918
Updated: 2026-09-29T13:57:17.253Z
Status : Analyzed
Published: 2026-09-28T21:17:13.410
Modified: 2026-10-07T20:59:17.860
Link: CVE-2026-101918