CVE-2026-55666

CRITICAL

Rocket.Chat: Email Parameter Fallback Leads To Account Takeover Within Apple OAuth

Title source: cna

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.

References (1)

Core 1

Core References

X_Refsource_Confirm x_refsource_confirm

https://github.com/RocketChat/Rocket.Chat/security/advisories/GHSA-wx3c-76rf-wpwf

Scores

CVSS v4 9.3

EPSS 0.0029

EPSS Percentile 21.8%

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact total

Details

CWE

CWE-287 CWE-288

Status published

Products (7)

RocketChat/Rocket.Chat < 7.10.13

RocketChat/Rocket.Chat >= 7.11.0-rc.0, < 8.0.7

RocketChat/Rocket.Chat >= 8.1.0-rc.0, < 8.1.6

RocketChat/Rocket.Chat >= 8.2.0-rc.0, < 8.2.6

RocketChat/Rocket.Chat >= 8.3.0-rc.0, < 8.3.6

RocketChat/Rocket.Chat >= 8.4.0-rc.0, < 8.4.4

RocketChat/Rocket.Chat >= 8.5.0-rc.0, < 8.5.1

Published Jun 24, 2026

Tracked Since Jun 25, 2026