Medium severity · published Sep 14, 2026
CVE-2026-90927
filebrowser through 2.63.23 Denial of Service via unbounded WebSocket message
6.5
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
filebrowser · filebrowser
through 2.63.23 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-90927
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-90927
github.com
https://github.com/filebrowser/filebrowser/security/advisories/GHSA-39cx-23x9-5c8p
www.vulncheck.com
https://www.vulncheck.com/advisories/filebrowser-through-2.63.23-denial-of-service-via-unbounded-websocket-message
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