CVE-2026-55666
Received Received - Intake
Account Takeover via Apple OAuth JWT in Rocket.Chat

Publication date: 2026-06-24

Last updated on: 2026-06-24

Assigner: GitHub, Inc.

Description
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.
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Meta Information
Published
2026-06-24
Last Modified
2026-06-24
Generated
2026-06-25
AI Q&A
2026-06-25
EPSS Evaluated
N/A
NVD
CVE-2026-55666
Affected Vendors & Products
Showing 7 associated CPEs
Vendor Product Version / Range
rocket.chat rocket.chat 8.5.1
rocket.chat rocket.chat 8.4.4
rocket.chat rocket.chat 8.3.6
rocket.chat rocket.chat 8.2.6
rocket.chat rocket.chat 8.1.6
rocket.chat rocket.chat 8.0.7
rocket.chat rocket.chat 7.10.13
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-287 When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
CWE-288 The product requires authentication, but the product has an alternate path or channel that does not require authentication.
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Executive Summary

This vulnerability exists in Rocket.Chat versions 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 the Apple OAuth login handler.

The issue is in the handleIdentityToken function that parses a JWT issued by Apple during the OAuth flow. The code expects the JWT to contain an email parameter.

If the JWT does not contain an email address, the application incorrectly falls back to accepting an arbitrary email value supplied directly in the request.

Attackers can exploit this by forging Apple JWTs without an email address and supplying arbitrary email values, allowing them to carry out account takeover attacks.

Impact Analysis

This vulnerability can lead to account takeover attacks.

An attacker can forge Apple JWTs without an email and supply arbitrary email addresses to gain unauthorized access to user accounts.

This compromises the security and privacy of user accounts on the affected Rocket.Chat instances.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade Rocket.Chat to one of the fixed versions: 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, or 7.10.13.

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