USN-8823-1: PyJWT vulnerabilities
Ubuntu patched PyJWT flaws that can enable SSRF and JWT signature bypass on LTS releases.
Ubuntu security notice USN-8823-1 covers vulnerabilities in PyJWT. CVE-2026-48522, affecting Ubuntu 22.04, 24.04, and 26.04 LTS, can let a remote attacker abuse PyJWKClient URI handling for server-side request forgery or exposure of sensitive local files. CVE-2026-48523, limited to Ubuntu 26.04 LTS, can let an attacker bypass cryptographic signature verification and forge JSON Web Tokens. The notice does not report active exploitation.
- CVE-2026-48522 may allow SSRF or local file exposure via PyJWKClient.
- CVE-2026-48523 can bypass signature checks and forge JWTs on Ubuntu 26.04.
- The notice does not report exploitation in the wild.
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
CVE-2026-48523+1 related CVE | PyJWT: There is a verifier-side algorithm allow-list bypass when jwt.decode() or jwt.decode_complete() are called with a PyJWK key. The… | 5.4 group max | <1% | PoC |
From the original article
It was discovered that PyJWT incorrectly handled certain URIs when using PyJWKClient. A remote attacker could possibly use this issue to perform server-side request forgery (SSRF) or expose sensitive local files. This issue only affected Ubuntu 22.
ubuntu.com
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