Cockpit: cockpit: denial of service via unbounded connection thread spawning
Summary
| CVE | CVE-2026-91149 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-18 17:17:05 UTC |
| Updated | 2026-11-09 16:17:35 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.004310000 probability, percentile 0.374190000 (date 2026-11-04)
Problem Types: CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | unaffected 0:356.4-1.el10_2 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:356.4-1.el9_8 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:356.4-1.el9_8 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Dev Spaces | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Dev Spaces | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Dev Spaces | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:96250 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-91149 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:94533 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was discovered by AISLE Research and Found by AISLE in partnership with Red Hat. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-18T03:32:25.000Z | Reported to Red Hat. |
| CNA | 2026-09-18T16:28:00.000Z | Made public. |
Workarounds
CNA: Restrict network access to the Cockpit listener (TCP port 9090) to trusted management networks or localhost only, using host firewall rules such as firewalld zones or iptables rules that limit which sources may reach port 9090. If remote access to the Cockpit web console is not required, disable the listener entirely with `systemctl disable --now cockpit.socket`. External connection-rate or concurrency limits in front of TCP port 9090, such as those enforced by a firewall or reverse proxy, further reduce exploitability. Lowering the service's task or file-descriptor ceilings can reduce the blast radius, but does not correct the missing concurrency bound in the cockpit-tls accept path; fixes are being pursued for the affected product streams.