CVE-2026-90927 filebrowser through 2.63.23 Denial of Service via unbounded WebSocket message
Authenticated attackers can exhaust server memory by sending oversized WebSocket messages to the command handler, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90927?
CVE-2026-90927 is a high-severity denial of service vulnerability in filebrowser, published on 14 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
filebrowser through 2.63.23 fails to limit WebSocket message size in the /api/command handler before checking permissions, allowing authenticated users to buffer arbitrarily large messages. Attackers can send oversized WebSocket messages to exhaust server heap memory and cause denial of service regardless of EnableExec setting or Execute permission.
Weakness: CWE-400
Which versions are affected by CVE-2026-90927?
How do I fix CVE-2026-90927?
No fix has been published for CVE-2026-90927 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-90927 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90927 exists.
Sources
Also known as GHSA-39cx-23x9-5c8p, GHSA-9f2h-f5v4-r5qq.