---
id: CVE-2026-91147
title: A flaw was found in `cockpit-ws`
summary: >-
  A flaw was found in `cockpit-ws`. This vulnerability allows a remote,
  unauthenticated attacker to cause a Denial of Service (DoS) by sending a
  specially crafted request. When the `WebService.UrlRoot` is configured and a
  request is made t…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-617
vendor: Red Hat
product: cockpit
affected:
  - cockpit (all versions)
  - cockpit (all versions)
  - cockpit (all versions)
  - cockpit (all versions)
  - devspaces/udi-base-rhel10 (all versions)
  - devspaces/udi-base-rhel9 (all versions)
  - devspaces/udi-rhel9 (all versions)
published: '2026-09-18'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T17:17:28.777'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91147'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91147'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2479230'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2479230'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91147.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91147'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91147'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.00511
epssPercentile: 0.41103
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-22T16:23:18.184024Z'
ingestedAt: '2026-09-18T16:45:41.403Z'
---

## Overview

A flaw was found in `cockpit-ws`. This vulnerability allows a remote, unauthenticated attacker to cause a Denial of Service (DoS) by sending a specially crafted request. When the `WebService.UrlRoot` is configured and a request is made to the exact URL-root prefix without a trailing slash, `cockpit-ws` can terminate unexpectedly. This issue leads to the unavailability of the Cockpit web service.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Dev Spaces · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Dev Spaces, … · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91147.json)