Description
A flaw was found in Cockpit. This vulnerability allows a remote attacker, without prior authentication, to send specially crafted fragmented WebSocket messages. These messages accumulate without a total-size limit, leading to unbounded memory exhaustion and a denial of service in the `cockpit-ws` service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 10.2 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 9.8 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat OpenShift Dev Spaces | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | cockpit | 372-1 | — |
| Debian 13 | cockpit | No fix yet | — |
| Debian 12 | cockpit | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | cockpit | No fix yet | — |
| Ubuntu 26.04 LTS | cockpit | No fix yet | — |
| Ubuntu 24.04 LTS | cockpit | No fix yet | — |
| Ubuntu 22.04 LTS | cockpit | No fix yet | — |
| Ubuntu 20.04 LTS | cockpit | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | cockpit | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | cockpit +7 | 366.1.1-1.el10_3 | RHSA-2026:99600 |
| RHEL 9 | cockpit +7 | 366.1.1-1.el9_9 | RHSA-2026:99602 |
| RHEL 8 | cockpit +4 | 310.10.2-1.el8_10 | RHSA-2026:99603 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.2 EUS | cockpit +7 | 356.4.1-1.el10_2 | RHSA-2026:99599 |
| RHEL 9.8 EUS | cockpit +7 | 356.4.1-1.el9_8 | RHSA-2026:99601 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 9 | cockpit +7 | 366.1.1-1.el9_9.rocky.0.1 | RLSA-2026:99602 |
| Rocky Linux 8 | cockpit +4 | 310.10.2-1.el8_10 | RLSA-2026:99603 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | cockpit +4 | 310.10.2-1.0.1.el8_10 | ELSA-2026-99603 |
Advisories 9
- RHSA-2026:99600 Red Hat Security Advisory: cockpit security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:99603 Red Hat Security Advisory: cockpit security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:99602 Red Hat Security Advisory: cockpit security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:99599 Red Hat Security Advisory: cockpit security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:99601 Red Hat Security Advisory: cockpit security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RLSA-2026:99602 Important: cockpit security update Rocky Linux Security Advisories · Nov 13, 2026
- RLSA-2026:99603 Important: cockpit security update Rocky Linux Security Advisories · Nov 13, 2026
- ELSA-2026-99603 Important: cockpit security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 13, 2026
- WID-SEC-2026-4542 Red Hat Enterprise Linux: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
References
- RHSA-2026:99599 vendor-advisory
- RHSA-2026:99600 vendor-advisory
- RHSA-2026:99601 vendor-advisory
- RHSA-2026:99602 vendor-advisory
- RHSA-2026:99603 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-91150 vdb-entry
- RHBZ#2478436 issue-tracking
- https://github.com/cockpit-project/cockpit/commit/4bc66ac3e5b4923528f1ac89517a009b7bc90f93
- https://github.com/cockpit-project/cockpit/releases/tag/372