5.3Medium
CVE-2026-85622
AppFlowy-Cloud through 0.9.64 fails to validate workspace membership when establishing WebSocket connections in the establish_ws_connection_v2 handler, allowing authenticated users to bind sessions to workspaces they do not belong to. Attackers can send sync Manifest messages with victim object identifiers to read full document or database state from collaborations in other workspaces without victim involvement.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 24% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 5.3 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N- CVSS v4
- 6.0
- Weakness
- CWE-863
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-04
- Last modified
- 2026-09-10
- Sources
- NVD