CVE-2025-68667

Conduit is a chat server powered by Matrix. A vulnerability that affects a number of Conduit-derived homeservers allows a remote, unauthenticated attacker to force the target server to cryptographically sign arbitrary membership events. Affected products include Conduit prior to version 0.10.10, continuwuity prior to version 0.5.0, Grapevine prior to commit `9a50c244`, and tuwunel prior to version 1.4.8. The flaw exists because the server fails to validate the origin of a signing request, provided the event's state_key is a valid user ID belonging to the target server. Attackers can forge "leave" events for any user on the target server. This forcibly removes users (including admins and bots) from rooms. This allows denial of service and/or the removal of technical protections for a room (including policy servers, if all users on the policy server are removed). Attackers can forge "invite" events from a victim user to themselves, provided they have an account on a server where there is an account that has the power level to send invites. This allows the attacker to join private or invite-only rooms accessible by the victim, exposing confidential conversation history and room state. Attackers can forge "ban" events from a victim user to any user below the victim user's power level, provided the victim has the power level to issue bans AND the target of the ban resides on the same server as the victim. This allows the attacker to ban anyone in a room who is on the same server as the vulnerable one, however cannot exploit this to ban users on other servers or the victim themself. Conduit fixes the issue in version 0.10.10. continuwuity fixes the issue in commits `7fa4fa98` and `b2bead67`, released in 0.5.0. tuwunel fixes the issue in commit `dc9314de1f8a6e040c5aa331fe52efbe62e6a2c3`, released in 1.4.8. Grapevine fixes the issue in commit `9a50c2448abba6e2b7d79c64243bb438b351616c`. As a workaround, block access to the `PUT /_matrix/federation/v2/invite/{roomId}/{eventId}` endpoint using your reverse proxy.
CVSS

No CVSS.

Configurations

No configuration.

History

26 Dec 2025, 21:15

Type Values Removed Values Added
Summary (en) continuwuity is a Matrix homeserver written in Rust. Prior to version 0.5.0, this vulnerability allows a remote, unauthenticated attacker to force the target server to cryptographically sign arbitrary membership events. The flaw exists because the server fails to validate the origin of a signing request, provided the event's state_key is a valid user ID belonging to the target server. This issue has been patched in version 0.5.0. A workaround for this issue involves blocking access to the PUT /_matrix/federation/v2/invite/{roomId}/{eventId} endpoint using the reverse proxy. (en) Conduit is a chat server powered by Matrix. A vulnerability that affects a number of Conduit-derived homeservers allows a remote, unauthenticated attacker to force the target server to cryptographically sign arbitrary membership events. Affected products include Conduit prior to version 0.10.10, continuwuity prior to version 0.5.0, Grapevine prior to commit `9a50c244`, and tuwunel prior to version 1.4.8. The flaw exists because the server fails to validate the origin of a signing request, provided the event's state_key is a valid user ID belonging to the target server. Attackers can forge "leave" events for any user on the target server. This forcibly removes users (including admins and bots) from rooms. This allows denial of service and/or the removal of technical protections for a room (including policy servers, if all users on the policy server are removed). Attackers can forge "invite" events from a victim user to themselves, provided they have an account on a server where there is an account that has the power level to send invites. This allows the attacker to join private or invite-only rooms accessible by the victim, exposing confidential conversation history and room state. Attackers can forge "ban" events from a victim user to any user below the victim user's power level, provided the victim has the power level to issue bans AND the target of the ban resides on the same server as the victim. This allows the attacker to ban anyone in a room who is on the same server as the vulnerable one, however cannot exploit this to ban users on other servers or the victim themself. Conduit fixes the issue in version 0.10.10. continuwuity fixes the issue in commits `7fa4fa98` and `b2bead67`, released in 0.5.0. tuwunel fixes the issue in commit `dc9314de1f8a6e040c5aa331fe52efbe62e6a2c3`, released in 1.4.8. Grapevine fixes the issue in commit `9a50c2448abba6e2b7d79c64243bb438b351616c`. As a workaround, block access to the `PUT /_matrix/federation/v2/invite/{roomId}/{eventId}` endpoint using your reverse proxy.
References
  • () https://github.com/matrix-construct/tuwunel/commit/dc9314de1f8a6e040c5aa331fe52efbe62e6a2c3 -
  • () https://gitlab.com/famedly/conduit/-/releases/v0.10.10 -
  • () https://gitlab.computer.surgery/matrix/grapevine/-/commit/9a50c2448abba6e2b7d79c64243bb438b351616c -

23 Dec 2025, 23:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-12-23 23:15

Updated : 2025-12-29 15:58


NVD link : CVE-2025-68667

Mitre link : CVE-2025-68667

CVE.ORG link : CVE-2025-68667


JSON object : View

Products Affected

No product.

CWE
CWE-20

Improper Input Validation

CWE-441

Unintended Proxy or Intermediary ('Confused Deputy')