Is there a public exploit for CVE-2026-48522?

No public exploit for CVE-2026-48522 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-48522?

CVE-2026-48522 scores CVSS 4.2 (v3.1), rated medium. EPSS puts the chance of exploitation in the next 30 days at 0.22%.

What does CVE-2026-48522 affect?

CVE-2026-48522 affects jpadilla PyJWT.

4.2 Medium

PyJWT is a JSON Web Token implementation in Python.

CVE-2026-48522

[!NOTE] The library does not directly return non-HTTP(S) URI contents to the attacker; the chained "plant a JWKS to forge tokens" scenario described in the original report requires additional application-layer flaws (attacker write access to a filesystem path, untrusted jku derivation) that this fix does not address. Severity is scored for the scheme-acceptance bug in isolation. Summary PyJWKClient passes its uri argument directly to urllib.request.urlopen() which uses Python stdlib's default OpenerDirector registering HTTPHandler, HTTPSHandler, FTPHandler, FileHandler, and DataHandler. There is currently no documented option to restrict which schemes PyJWKClient will fetch. If an application's jku URL ingestion path accepts attacker-influenced URLs (e.g., from JWT header, configuration file, OAuth flow parameter), the attacker can: 1. Cause PyJWKClient to read arbitrary local files via file:// (SSRF on local filesystem) — the file's contents are passed to json.load. 2. Cause PyJWKClient to attempt FTP / data-URI fetches (broader SSRF surface). 3. Forge tokens that PyJWT verifies as valid — if the attacker can write to any path the JKU URL points at AND influences the URL, they…

Assessment

CVSS: 4.2 (v3.1)
Severity: Medium
EPSS: 0.22% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 May 2026
Last updated: 26 October 2026
Affected: jpadilla · pyjwt · PyJWT
Weakness: CWE-441, CWE-918
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N

At the source

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