7.5High

CVE-2026-91149

A flaw was found in Cockpit. An unauthenticated remote attacker can exploit this vulnerability by initiating and sustaining numerous simultaneous connections to the `cockpit-tls` service. This forces the service to create an unbounded number of detached threads, consuming system resources such as memory and file descriptors. The primary consequence is a denial of service (DoS), leading to degradation or complete unavailability of the Cockpit service for legitimate users.

What this means for your business

  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 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
7.5 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-770
Assigned by
secalert@redhat.com

Dates

Published
2026-09-18
Last modified
2026-09-18
Sources
NVD

References