CVE intelligence and bounded remediation

CVE-2025-68667 — Conduit is a chat server powered by Matrix

Critical CVSS 9.9

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…

Severity
Critical
CVSS
9.9 (4.0)
Published
2025-12-23
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-441

Affected products

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Matched remediation archetype

Server-side request forgery and unintended proxying

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory server-side URL fetchers, webhooks, importers, previews, redirects, proxies, and protocol handlers reachable from untrusted input.
  • Map egress paths to internal services, metadata endpoints, loopback, private address space, and privileged control planes.
  • Review DNS resolution, redirect, proxy, credential-forwarding, and URL parsing behavior without requesting sensitive targets.

Remediate safely

  • Replace arbitrary destinations with named integrations or a strict allowlist of schemes, hosts, ports, and paths.
  • Resolve and validate every destination and redirect hop, then enforce egress policy independently of application checks.
  • Remove ambient credentials and sensitive headers from fetchers; apply response size, time, and content limits.

Authoritative sources

Complete CVE record and remediation plan

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