A flaw has been found in warmcat libwebsockets up to 4.5.8. This issue affects the function lws_ssh_parse_plaintext of the file plugins/protocol_lws_ssh_base/sshd.c of the component SSH Protocol Handler. Executing a manipulation of the argument msg_len can lead to resource consumption. The attack may be launched remotely. The exploit has been published and may be used. This patch is called 3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498. A patch should be applied to remediate this issue.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html
References
- https://github.com/biniamf/pocs/blob/main/libwebsockets_sshd-parse-ic-unbounded-alloc/poc_sshd_unbounded_alloc.py
- https://github.com/biniamf/pocs/tree/main/libwebsockets_sshd-parse-ic-unbounded-alloc
- https://github.com/warmcat/libwebsockets/
- https://github.com/warmcat/libwebsockets/commit/3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498
- https://vuldb.com/cve/CVE-2026-10650
- https://vuldb.com/submit/830261
- https://vuldb.com/vuln/367955
- https://vuldb.com/vuln/367955/cti