Vulnerability · Published Jun 2, 2026 · Assigned by VulDB
CVE-2026-10650warmcat libwebsockets SSH Protocol sshd.c lws_ssh_parse_plaintext resource consumption
Medium 5.3
In plain English
A medium-severity uncontrolled resource consumption in libwebsockets from warmcat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libwebsockets | no fix listed | DEBIAN-CVE-2026-10650 |
| Debian:13 | libwebsockets | 4.3.5-1+deb13u2 | DEBIAN-CVE-2026-10650 |
| Debian:14 | libwebsockets | 4.3.5-5 | DEBIAN-CVE-2026-10650 |
| Ubuntu:25.10 | libwebsockets | no fix listed | UBUNTU-CVE-2026-10650 |
| Ubuntu:26.04:LTS | libwebsockets | 4.3.5-3ubuntu1.1 | USN-8822-1 |
| Ubuntu:26.04:LTS | libwebsockets | 4.3.5-3ubuntu1.1 | UBUNTU-CVE-2026-10650 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| warmcat | libwebsockets | 4.5.04.5.14.5.24.5.34.5.44.5.54.5.64.5.7 |
Weakness: CWE-400, CWE-404 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
References
- VDB-367955 | warmcat libwebsockets SSH Protocol sshd.c lws_ssh_parse_plaintext resource consumption vdb-entry, technical-description
- VDB-367955 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- CVE-2026-10650 | CVE Analysis and Report third-party-advisory
- Submit #830261 | warmcat libwebsockets 4.5.99-v4.5.0-382-g4a63b9333 Uncontrolled Memory Allocation third-party-advisory
- https://github.com/biniamf/pocs/tree/main/libwebsockets_sshd-parse-ic-unbounded-alloc exploit
- https://github.com/biniamf/pocs/blob/main/libwebsockets_sshd-parse-ic-unbounded-alloc/poc_sshd_unbounded_alloc.py exploit
- https://github.com/warmcat/libwebsockets/commit/3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498 patch
- https://github.com/warmcat/libwebsockets/ product