# CVE-2026-48522: python3-jwt: PyJWT is a JSON Web Token implementation in Python

CVE-2026-48522 is fixed in 4 products on 1 platform, first by python3-jwt 2.3.0-1ubuntu0.4, released May 28, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-48522
- Priority: Routine
- CVSS: 4.2 (Medium)
- EPSS: 0.0022
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 28, 2026

## Description

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, 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 cause PyJWKClient to read arbitrary local files via file:// (SSRF on local filesystem), cause PyJWKClient to attempt FTP / data-URI fetches (broader SSRF surface), or forge tokens that PyJWT verifies as valid. 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. This vulnerability is fixed in 2.13.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pyjwt Debian 14 | 2.13.0-1 | [DEBIAN-CVE-2026-48522](https://patchblox.com/security/data/fix/linux/debian-cve-2026-48522.md) | May 28, 2026 |
| Linux | python-PyJWT opensuse-leap 16.0 | 2.12.1-160000.2.1 | [OPENSUSE-SU-2026:21095-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21095-1.md) | Jun 19, 2026 |
| Linux | python-PyJWT sles 15.6 | 2.4.0-150200.3.14.1 | [SUSE-SU-2026:2627-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2627-1.md) | Jun 25, 2026 |
| Linux | python-PyJWT sles 15.7 | 2.4.0-150200.3.14.1 | [SUSE-SU-2026:2627-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2627-1.md) | Jun 25, 2026 |
| Linux | python-PyJWT sles 16.0 | 2.12.1-160000.2.1 | [SUSE-SU-2026:22170-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22170-1.md) | Jun 19, 2026 |
| Linux | python3-jwt Ubuntu 22.04.1 LTS (jammy) | 2.3.0-1ubuntu0.4 | [python3-jwt 2.3.0-1ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-jwt-2.3.0-1ubuntu0.4.md) | May 28, 2026 |
| Linux | python3-jwt Ubuntu 24.04.5 LTS (noble) | 2.7.0-1ubuntu0.2 | [python3-jwt 2.7.0-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-jwt-2.7.0-1ubuntu0.2.md) | May 28, 2026 |
| Linux | python3-jwt Ubuntu 26.04.1 LTS (resolute) | 2.10.1-4ubuntu1.1 | [python3-jwt 2.10.1-4ubuntu1.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-jwt-2.10.1-4ubuntu1.1.md) | May 28, 2026 |
| Linux | python3-jwt amzn 2023 | 2.4.0-1.amzn2023.0.5 | [ALAS2023-2026-2051](https://patchblox.com/security/data/fix/linux/alas2023-2026-2051.md) | Aug 17, 2026 |
| Linux | python3-jwt+crypto amzn 2023 | 2.4.0-1.amzn2023.0.5 | [ALAS2023-2026-2051](https://patchblox.com/security/data/fix/linux/alas2023-2026-2051.md) | Aug 17, 2026 |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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