SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-45689

Prior to 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11, an unauthenticated network attacker obtains a valid Rocket.Chat OAuth access token for an arbitrary user by sending a single HTTP POST with MongoDB query operators to /oauth/token.

CRITICAL 9.1EPSS 0.53%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11, an unauthenticated network attacker obtains a valid Rocket.Chat OAuth access token for an arbitrary user by sending a single HTTP POST with MongoDB query operators to /oauth/token. The Rocket.Chat OAuth2 server does not validate that grant parameters are strings before forwarding them to findOne({...}) against the oauth_apps and oauth_access_tokens collections, so an attacker substitutes {"$ne": null} for client_id, client_secret, and refresh_token and receives a freshly minted {access_token, refresh_token} pair bound to whichever user's refresh token Mongo returned first. The resulting access token is a first-class bearer credential against the full /api/v1/* surface as that user. By iterating with $nin / $regex operators the attacker walks the entire oauth_access_tokens collection, collecting one fresh access token per user per request. If any matched token belongs to an admin, the stolen bearer gives full admin API access (including Apps-Engine app installation, i.e. server-side code execution). No account, credentials, userId, or prior interaction with the instance are required. This vulnerability is fixed in 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.53% probability · 43th percentile
CISA KEV
Not listed
Weakness
CWE-943
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.