Cockpit WebSocket Fragmentation DoS via Unbounded Memory Exhaustion
CVE-2026-91150 Published on November 11, 2026
Cockpit: cockpit: denial of service via unbounded fragmented websocket messages
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.
Vulnerability Analysis
CVE-2026-91150 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public. 176 days later.
Weakness Type
Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.
Products Associated with CVE-2026-91150
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Affected Versions
Red Hat Enterprise Linux 10:- Version 0:366.1.1-1.el10_3 and below * is unaffected.
- Version 0:356.4.1-1.el10_2 and below * is unaffected.
- Version 0:310.10.2-1.el8_10 and below * is unaffected.
- Version 0:366.1.1-1.el9_9 and below * is unaffected.
- Version 0:366.1.1-1.el9_9 and below * is unaffected.
- Version 0:356.4.1-1.el9_8 and below * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.