CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-91150 Cockpit: cockpit: denial of service via unbounded fragmented websocket messages
High (7.5) in red hat. EPSS 1.1% estimated probability of exploitation activity in the next 30 days.
On this page
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.
Severity
- EPSS
- 1.1% estimated probability of exploitation activity in the next 30 days; 67th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CWE
- CWE-770 Allocation of Resources Without Limits or Throttling
- Published
- Modified
- Assigned by
- redhat (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- red hat:red hat enterprise linux 10
- red hat:red hat enterprise linux 10.2 extended update support
- red hat:red hat enterprise linux 7
- 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 openshift dev spaces
Versions
From the CNA's record in the CVE List.
Fixed in
| Product | Fixed in |
|---|---|
| Red Hat Enterprise Linux 10 | 0:366.1.1-1.el10_3 |
| Red Hat Enterprise Linux 10.2 Extended Update Support | 0:356.4.1-1.el10_2 |
| Red Hat Enterprise Linux 8 | 0:310.10.2-1.el8_10 |
| Red Hat Enterprise Linux 9 | 0:366.1.1-1.el9_9 |
| Red Hat Enterprise Linux 9.8 Extended Update Support | 0:356.4.1-1.el9_8 |
Fix and patched versions
- Red Hat Red Hat Enterprise Linux 10: fixed in 0:366.1.1-1.el10_3
- Red Hat Red Hat Enterprise Linux 10.2 Extended Update Support: fixed in 0:356.4.1-1.el10_2
- Red Hat Red Hat Enterprise Linux 8: fixed in 0:310.10.2-1.el8_10
- Red Hat Red Hat Enterprise Linux 9: fixed in 0:366.1.1-1.el9_9
- Red Hat Red Hat Enterprise Linux 9.8 Extended Update Support: fixed in 0:356.4.1-1.el9_8
- Debian, Red Hat, Rocky Linux: fixed package versions per release
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13 | cockpit | no fix listed | DEBIAN-CVE-2026-91150 |
| Debian | 14 | cockpit | 372-1 | DEBIAN-CVE-2026-91150 |
| Ubuntu | 18.04:LTS, 20.04:LTS, 22.04:LTS and 3 more | cockpit | no fix listed | UBUNTU-CVE-2026-91150 |
| Red Hat | enterprise_linux:8::baseos | cockpit, cockpit-ws, cockpit-doc and 4 more | 0:310.10.2-1.el8_10 | RHSA-2026:99603 |
| Red Hat | enterprise_linux:9::appstream | cockpit-storaged, cockpit-packagekit | 0:366.1.1-1.el9_9 | RHSA-2026:99602 |
| Red Hat | enterprise_linux:9::baseos | cockpit, cockpit-ws, cockpit-doc and 5 more | 0:366.1.1-1.el9_9 | RHSA-2026:99602 |
| Red Hat | enterprise_linux:10.3 | cockpit, cockpit-ws, cockpit-doc and 7 more | 0:366.1.1-1.el10_3 | RHSA-2026:99600 |
| Red Hat | enterprise_linux_eus:10.2 | cockpit, cockpit-ws, cockpit-doc and 7 more | 0:356.4.1-1.el10_2 | RHSA-2026:99599 |
| Red Hat | rhel_eus:9.8::appstream | cockpit-storaged, cockpit-packagekit | 0:356.4.1-1.el9_8 | RHSA-2026:99601 |
| Red Hat | rhel_eus:9.8::baseos | cockpit, cockpit-ws, cockpit-doc and 5 more | 0:356.4.1-1.el9_8 | RHSA-2026:99601 |
| Rocky Linux | 8 | cockpit, cockpit-ws, cockpit-doc and 4 more | 0:310.10.2-1.el8_10 | RLSA-2026:99603 |
| Rocky Linux | 9 | cockpit, cockpit-ws, cockpit-doc and 7 more | 0:366.1.1-1.el9_9.rocky.0.1 | RLSA-2026:99602 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; Rocky Linux's errata, BSD-3-Clause. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat.
Red Hat
Red Hat rates this Important.
This is an Important denial of service flaw in Cockpit's `cockpit-ws` component. An unauthenticated remote attacker can exhaust process memory by sending specially crafted fragmented WebSocket messages, leading to service unavailability. This impact is significant because `cockpit-ws` is often exposed on Red Hat Enterprise Linux systems for remote management.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | cockpit | Affected | |
| Red Hat Enterprise Linux 7 | cockpit | Affected | |
| Red Hat Enterprise Linux 8 | cockpit | Affected | |
| Red Hat Enterprise Linux 9 | cockpit | Affected | |
| Red Hat OpenShift Dev Spaces | devspaces/udi-base-rhel10 | Affected | |
| Red Hat OpenShift Dev Spaces | devspaces/udi-base-rhel9 | Affected | |
| Red Hat OpenShift Dev Spaces | devspaces/udi-rhel9 | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-91150.
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-770 (20).
References
- https://access.redhat.com/errata/RHSA-2026:99599
- https://access.redhat.com/errata/RHSA-2026:99600
- https://access.redhat.com/errata/RHSA-2026:99601
- https://access.redhat.com/errata/RHSA-2026:99602
- https://access.redhat.com/errata/RHSA-2026:99603
- https://access.redhat.com/security/cve/CVE-2026-91150
- https://bugzilla.redhat.com/show_bug.cgi?id=2478436
- https://github.com/cockpit-project/cockpit/commit/4bc66ac3e5b4923528f1ac89517a009b7bc90f93
- https://github.com/cockpit-project/cockpit/releases/tag/372