CVE-2026-55759
HighCVSS 7.4Exploitation Probability (EPSS)
Low risk15th percentile — higher than 15% of all known CVEs
Summary
Vulnerability in Rocket.Chat's Apple Sign-In handler lacks JWT claims validation. An attacker who obtains a target user's Apple identity token (from server logs, intercepted sign-in flow, or another app sharing the same Apple developer team) can replay it to authenticate as that user with no expiration.
Risk Assessment
Risk involves account takeover without knowing the user's password, potentially leading to unauthorized access to sensitive messages, files, and other organizational resources.
Recommendation
Immediately upgrade Rocket.Chat to one of the patched versions: 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, or 7.10.13. After update, Apple Sign-In will properly validate all JWT claims.
Original NVD description (English source)
Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, Rocket.Chat's Apple Sign-In handler verifies JWT signatures but skips claims validation. Any Apple-signed JWT with a non-empty iss is accepted regardless of aud, exp, nbf, or nonce. An attacker who obtains a target user's Apple identity token (from server logs, an intercepted sign-in flow, or another application sharing the same Apple developer team) can replay it to authenticate as that user, with no expiration on the replay window. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.