{"id":"ghsa-ghsa-8m4g-j4wp-wgcg","seq":1708773,"kind":"advisory","title":"Authlib accepts an empty HMAC key, allowing JWS/JWT signature forgery (HS256/HS384/HS512)","url":"https://github.com/advisories/GHSA-8m4g-j4wp-wgcg","permalink":"https://vulnpulse.app/items/ghsa-ghsa-8m4g-j4wp-wgcg","summary":"影響: pip:Authlib < 1.9.1 → 1.9.1\nReporter: Cavan Loughran, Celvex Group Inc. Summary Authlib's symmetric (oct) key handling accepts an empty key (empty bytes b'' / empty string '') as a valid HMAC signing and verification key. An empty HMAC key produces a deterministic digest that any party can reproduce, so an attacker who knows (or can cause) the application to verify a token with an empty key can forge arbitrary tokens that pass HS256/HS384/HS512 signature verification. This is the Authlib member of the cross-language empty…","severity":"high","techs":["python"],"cves":["CVE-2026-114616"],"tags":["GHSA-8m4g-j4wp-wgcg","Authlib"],"source":{"id":"ghsa","name":"GitHub Advisory Database"},"published_at":"2026-10-27T16:09:22.000Z","fetched_at":"2026-10-27T21:03:52.214Z"}