cvedb.io
CVE-2021-39164
LOW · CVSS 3.1
EPSS exploitation probability: 0%
Published 2021-08-31T17:15:08.267 · Last modified 2026-06-17T04:03:13.710

Summary

Matrix is an ecosystem for open federated Instant Messaging and Voice over IP. In versions 1.41.0 and prior, unauthorised users can access the membership (list of members, with their display names) of a room if they know the ID of the room. The vulnerability is limited to rooms with `shared` history visibility. Furthermore, the unauthorised user must be using an account on a vulnerable homeserver that is in the room. Server administrators should upgrade to 1.41.1 or later in order to receive the patch. One workaround is available. Administrators of servers that use a reverse proxy could, with potentially unacceptable loss of functionality, block the endpoints: `/_matrix/client/r0/rooms/{room_id}/members` with `at` query parameter, and `/_matrix/client/unstable/rooms/{room_id}/members` with

Affected products

matrix — synapse

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.