EEF-CVE-2026-55735 漏洞概述 Guardian.revoke/3 函数在验证未签名的令牌时存在缺陷，允许攻击者伪造令牌并撤销受害者的会话。 影响范围 受影响的版本：Guardian 1.0.0 到 2.4.1 漏洞类型：未经验证的加密签名 修复方案 在调用 Guardian.revoke/3 之前，先调用 （或其无过期验证变体），确保只有签名有效的令牌才能被撤销。拒绝带有无效签名的令牌，并在应用边界处进行验证。 POC代码 ```elixir Guardian.revoke/3 in lib/guardian.ex decodes the supplied token with peek/1, which performs no signature verification (it only base64-decodes the JWT header and payload). The resulting unverified claims are forwarded directly to the configured token module's revoke callback and the implementation's on_revoke callback, a state-mutating sink. The sibling operations refresh/2 and exchange/4 both call decode_and_verify first, so the signature is checked before anything acts on the claims; revoke/3 is the only state-mutating path that acts on claims without verifying the signature. An attacker who knows or guesses a victim's identifying claim values (jti, sub) can forge a JWT carrying those claims, sign it with an arbitrary key, and submit it to any endpoint that funnels a caller-supplied token into Guardian.revoke/3 (the standard logout / session-revocation pattern). When the token module mutates state keyed by the claims (whitelist deletion or blacklist insertion, for example a GuardianDB-style store), the victim's legitimate session is evicted. This is an unauthenticated session-revocation denial of service: the attacker never needs the signing secret.