VULNERABILITY INTELLIGENCE
CVE-2026-63097
CVSS score4.3 MEDIUM
EPSS probability0.27%
CISA KEVNot currently listed
Published2026-07-17
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Description
Dendrite through 0.13.8 contains an improper access control vulnerability in the syncapi /context endpoint (syncapi/routing/context.go) that allows authenticated local users to access post-leave room state events by exploiting a flawed membership check that evaluates only the RoomExists field while ignoring IsInRoom, HasBeenInRoom, and Membership fields. Attackers who have left a room can call the rooms context API endpoint for a previously permitted event and receive unfiltered current room state that the /messages and /sync endpoints correctly withhold.
Weakness classification
- disclosure@vulncheck.com: CWE-863