CVE-2026-91149
Cockpit: cockpit: denial of service via unbounded connection thread spawning
What happened?
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.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| cockpitRed Hat | unaffected: 0:356.4-1.el9_8 to < * | See vendor advisory |
| cockpitRed Hat | unaffected: 0:356.4-1.el9_8 to < * | See vendor advisory |
| cockpitRed Hat | Default status: affected | See vendor advisory |
| cockpitRed Hat | Default status: affected | See vendor advisory |
| cockpitRed Hat | Default status: affected | See vendor advisory |
| devspaces/udi-base-rhel10Red Hat | Default status: unaffected | See vendor advisory |
| devspaces/udi-base-rhel9Red Hat | Default status: unaffected | See vendor advisory |
| devspaces/udi-rhel9Red Hat | Default status: unaffected | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.