What is CVE-2026-55759?

CVE-2026-55759 is a high-severity vulnerability in Rocketchat Rocket.chat, classified under Improper Authentication. CVSS score: 7.4/10. Published 2026-06-24.

How severe is CVE-2026-55759?

High severity. CVSS v3 base score is 7.4 out of 10.

Auth bypass in Rocketchat Rocket.chat

CVE-2026-55759

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…

Vulnerability class: Broken Authentication

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Rocketchat Rocket.chat — versions >= 8.5.0-rc.0, < 8.5.1, >= 8.4.0-rc.0, < 8.4.4, >= 8.3.0-rc.0, < 8.3.6

Weakness classification (CWE)

CWE-287 — Improper Authentication
CWE-294 — Authentication Bypass by Capture-replay

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-55759?: CVE-2026-55759 is a high-severity vulnerability in Rocketchat Rocket.chat, classified under Improper Authentication. CVSS score: 7.4/10. Published 2026-06-24.
How severe is CVE-2026-55759?: High severity. CVSS v3 base score is 7.4 out of 10.