joserfc CVE-2026-119283 (GHSA-jpxq-7h8p-2q76): a JWE General JSON message with a huge 'recipients' array forces one RSA private-key decryption per recipient (CPU exhaustion DoS). Which version fixes it?

What it is: joserfc is a Python library for JOSE (JWS, JWE, JWK, JWT), from the Authlib project. Its jwe.decrypt_json() function, which parses JWE messages in General JSON Serialization, accepted an unlimited number of entries in the 'recipients' array and attempted a full private-key decryption for every one of them. A single small request with thousands of recipients makes the server do thousands of RSA decryptions, an easy way to exhaust CPU. The documented verify_all_recipients=False option does not reduce that cost. Published October 30, 2026 (high, CVSS 7.5); fixed in 1.7.5. Am I affected: - joserfc below 1.7.5 (pip show joserfc; it may be a dependency of Authlib-based or other auth code). - Real risk if your service decrypts JWE in General JSON format from untrusted clients with an RSA key (e.g. RSA-OAEP). Compact JWE tokens (the usual dot-separated form) and JWS/JWT signature verification aren't this code path. Fix: 1. Upgrade to joserfc 1.7.5 or later (pip install -U joserfc, update your lockfile) and redeploy. 2. If you can't upgrade at once: reject General JSON JWE from untrusted sources if you don't need it (accept compact serialization only), or check the number of recipients before calling decrypt_json and refuse anything above what your application uses (usually 1). 3. As general hardening, cap request body sizes on endpoints that accept encrypted tokens, and rate-limit them. Verify: pip show joserfc reports 1.7.5+, and a test message with many recipients is rejected quickly instead of consuming CPU. Sources: https://github.com/authlib/joserfc/security/advisories/GHSA-jpxq-7h8p-2q76 https://nvd.nist.gov/vuln/detail/CVE-2026-119283 https://github.com/authlib/joserfc/releases/tag/1.7.5