CVE-2026-101917
Consequently, attacker traffic can amplify outbound requests to the configured JWKS endpoint.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT get_signing_key_from_jwt is affected because unknown kid misses force refreshes without a negative cache or minimum refresh interval. This occurs when unauthenticated tokens repeatedly use the same unknown kid or varying kid values absent from the cached JWKS. As a result, each cache miss causes PyJWKClient to refresh the JWKS. Consequently, attacker traffic can amplify outbound requests to the configured JWKS endpoint. This issue is fixed in version 2.14.0.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.43% probability · 37th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- pyjwt project/pyjwt
- Source
- security-advisories@github.com
EPSS moved from 0.4% on 29 September 2026 to 0.4% on 26 October 2026.
References
- https://github.com/jpadilla/pyjwt/commit/ba4853a75fb9676362da17f67d0f64bd18afd4e1Patch
- https://github.com/jpadilla/pyjwt/releases/tag/2.14.0Product, Release Notes
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-2gx3-rcp4-g85qExploit, Vendor Advisory
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-2gx3-rcp4-g85qExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.