CVE-2026-48524: PyJWT: PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values (DoS)
jpadilla · pyjwt
Affected: jpadilla pyjwt · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 34% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- jpadilla · pyjwt< 2.13.0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
CoverageNo articles yet
No CyberSIXT article names CVE-2026-48524 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.