CVE-2026-48524

Name	CVE-2026-48524
Description	PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1138191

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pyjwt (PTS)	bullseye	1.7.1-2	vulnerable
	bullseye (security)	1.7.1-2+deb11u1	vulnerable
	bookworm, bookworm (security)	2.6.0-1+deb12u1	vulnerable
	trixie (security), trixie	2.10.1-2+deb13u1	vulnerable
	forky, sid	2.12.1-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
pyjwt	source	(unstable)	(unfixed)			1138191

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-fhv5-28vv-h8m8