CVE-2026-101917

PyJWT: PyJWKClient still amplifies unauthenticated JWKS fetches on unknown kid values (incomplete fix of CVE-2026-48524)

CVE-2026-101917 is fixed in 4 products on 1 platform, first by python3-jwt 2.10.1-4ubuntu1.3, released September 28, 2026. It is not reported as exploited. Patch Radar priority: High.

High

CVSS

7.5

Moderate

Exploitation

None reported

No vendor assessment

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0043

37th percentile

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.

Where it's fixed

Product	Fixed in	Fix	Released
Linux
pyjwt · Debian 14	2.14.0-1	DEBIAN-CVE-2026-101917	Oct 4, 2026
python-PyJWT · opensuse-leap 16.0	2.12.1-160000.3.1	OPENSUSE-SU-2026:22074-1	Nov 7, 2026
python-PyJWT · sles 15.6	2.8.0-150400.8.20.1	SUSE-SU-2026:5064-1	Nov 7, 2026
python-PyJWT · sles 15.7	2.8.0-150400.8.20.1	SUSE-SU-2026:5064-1	Nov 7, 2026
python-PyJWT · sles 16.0	2.12.1-160000.3.1	SUSE-SU-2026:24219-1	Nov 7, 2026
python3-jwt · Ubuntu 22.04.1 LTS (jammy)	2.3.0-1ubuntu0.6	python3-jwt 2.3.0-1ubuntu0.6	Oct 27, 2026
python3-jwt · Ubuntu 24.04.5 LTS (noble)	2.7.0-1ubuntu0.4	python3-jwt 2.7.0-1ubuntu0.4	Oct 27, 2026
python3-jwt · Ubuntu 26.04.1 LTS (resolute)	2.10.1-4ubuntu1.3	python3-jwt 2.10.1-4ubuntu1.3	Sep 28, 2026
python3-jwt · amzn 2023	2.4.0-1.amzn2023.0.6	ALAS2023-2026-3298	Nov 7, 2026
python3-jwt+crypto · amzn 2023	2.4.0-1.amzn2023.0.6	ALAS2023-2026-3298	Nov 7, 2026

Details

Published
September 28, 2026
Weakness
Allocation of Resources Without Limits or Throttling
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-101917

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