CVE-2026-91147
Cockpit: cockpit: denial of service in `cockpit-ws` due to url-root handling without a trailing slash
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.
Fixes and workarounds
Workaround
A code fix is being pursued for the affected streams. Until updated packages are available, avoid configuring a non-empty [WebService] UrlRoot in cockpit-ws where feasible. If a non-empty UrlRoot is required, configure the front-end proxy or TLS terminator in front of cockpit-ws to rewrite or redirect requests for the exact configured prefix (for example, /cockpit) to the trailing-slash form (for example, /cockpit/) before forwarding them, so the exact-prefix request never reaches cockpit-ws unnormalized. Deployments whose front end already normalizes or redirects such requests are not exposed through that route.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Enterprise Linux 8 Red Hat cockpit
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:310.10-1.el8_10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 10 Red Hat cockpit
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 7 Red Hat cockpit
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat cockpit
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Dev Spaces Red Hat devspaces/udi-base-rhel10
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Dev Spaces Red Hat devspaces/udi-base-rhel9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Dev Spaces Red Hat devspaces/udi-rhel9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA: redhat |
Exploit evidence
- https://bugzilla.redhat.com/show_bug.cgi?id=2479230
exploit · ADP: CISA-ADP
References
- https://access.redhat.com/errata/RHSA-2026:94485CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-91147CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2479230CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2479230ADP: CISA-ADP · exploit
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