# CVE-2026-76235: Cockpit-ws: cockpit: cockpit-ws: unauthenticated remote memory leak via cockpitlang cookie in send_login_html

Status: published. Published: 2026-08-19. Updated: 2026-11-03.

A memory leak flaw was found in cockpit-ws. The login page handler leaks a heap allocation on every unauthenticated request that carries a CockpitLang cookie, allowing a remote unauthenticated attacker to exhaust memory on the host and cause a denial of service.

## Remediation

- workaround: Restrict network access to the cockpit port to trusted clients until a fix is available. No configuration-level mitigation removes the flaw entirely, since the login page must remain reachable without authentication. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 8 (cockpit): ≥ 0:310.10-1.el8_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (cockpit): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (cockpit): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (cockpit): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Dev Spaces (devspaces/udi-base-rhel10): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Dev Spaces (devspaces/udi-base-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Dev Spaces (devspaces/udi-rhel9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.61% as of 2026-11-03; percentile 49.12%

- SSVC: exploitation none; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-401

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:94485 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-76235 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2519497 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-76235; retrieved 2026-11-03; source updated 2026-11-03

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-76235; retrieved 2026-11-03; source updated Not reported

Revision: 4f06a1b87a96af93d2f1307006231e10e2d17716d66f8e8ed2ebaba3f2923f33

Canonical: https://y2.dev/cve/CVE-2026-76235

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