CVE-2026-91147: Cockpit: cockpit: denial of service in `cockpit-ws` due to url-root handling without a trailing slash
Vulnerability summary
CVE-2026-91147 is a medium (CVSS 5.9) Reachable Assertion vulnerability in cockpit. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 34.6% of scored vulnerabilities.
Not severe (CVSS 5.9, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 18-09-2026PublishedVulnerability first disclosed.
- 03-11-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.40%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.40% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- cockpitAll versions (No fix recorded) | < 368-1
Ubuntu1 product
- cockpitAll versions (No fix recorded)
2 vendors · 2 products
