What happened
Element Web is a Matrix web client built using the Matrix React SDK. Element Web and Element Desktop before version 1.11.112 have insufficient validation of room predecessor links, allowing a remote attacker to attempt to impermanently replace a room's entry in the room list with an unrelated attacker-supplied room. While the effect of this is temporary, it may still confuse users into acting on incorrect assumptions. The issue has been patched and users should upgrade to 1.11.112. A reload/refresh will fix the incorrect room list state, removing the attacker's room and restoring the original room.
Affected versions
element-web: < 1.11.112 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.