---
cve: "CVE-2026-55666"
severity: "CRITICAL"
cvss: 9.3
epss: "30%"
vendor: "RocketChat"
kev: false
exploited: false
published: "2026-06-24 22:16:49"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T18:12:17+02:00"
---

# CVE-2026-55666

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 1651a370018d929d69c33fe665ab077dc70e4f52 (Commit)
- 3ab367adc463a88492e897a1349b83a156d1c1a0 (Commit)

## Referenzen

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

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-55666) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_