CVE-2026-55666
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk21th percentile — higher than 21% of all known CVEs
Summary
In Rocket.Chat prior to versions 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, in loginHandler.ts, handleIdentityToken parses a JWT from Apple during OAuth. If the JWT lacks an email, the app accepts an arbitrary email from the request, enabling account takeover.
Risk Assessment
An attacker can forge an Apple JWT without an email and take over a user account, leading to unauthorized access to organizational communications and data.
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.
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, in apps/meteor/app/apple/server/loginHandler.ts, handleIdentityToken parses a JWT issued by Apple during the OAuth flow. The try block checks for an email parameter. If the JWT does not contain an email address, the application falls back to accepting an arbitrary email value supplied directly in the request. Attackers are able to forge Apple JWTs that do not contain an email address and leverage this vulnerability to carry out account takeover attacks. 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.

