Is CVE-2026-10650 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-10650 being exploited in the wild.

How severe is CVE-2026-10650?

Medium severity, with a CVSS score of 5.3, published 2 June 2026.

Which products and versions are affected?

Warmcat Libwebsockets up to 4.5.8.

Is there a fix for CVE-2026-10650?

A patch was published on 2026-06-02: Patch commit 3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-10650 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-10650?

Check whether you run Warmcat Libwebsockets at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-10650: Warmcat libwebsockets resource consumption in SSH Protocol Handler

CVE-2026-10650 · Severity: medium · CVSS 5.3 · Published 2026-06-02

A vulnerability exists in the SSH protocol handler of libwebsockets, a networking library used by various applications to manage web and SSH connections. An unauthenticated remote attacker can send a specially crafted small packet that forces the server to allocate a large amount of memory. This can lead to a denial-of-service condition where the server crashes or becomes unresponsive due to memory exhaustion, potentially impacting business operations and service availability.

Technologies: Warmcat Libwebsockets. Vendors: Warmcat.

Quick answers

Is CVE-2026-10650 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-10650 being exploited in the wild.
How severe is CVE-2026-10650?: Medium severity, with a CVSS score of 5.3, published 2 June 2026.
Which products and versions are affected?: Warmcat Libwebsockets up to 4.5.8.
Is there a fix for CVE-2026-10650?: A patch was published on 2026-06-02: Patch commit 3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-10650 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-10650?: Check whether you run Warmcat Libwebsockets at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability in the SSH protocol plugin of libwebsockets (specifically in `plugins/protocol_lws_ssh_base/sshd.c`) stems from a missing upper-bound check on the `msg_len` argument within the `lws_ssh_parse_plaintext` function. An unauthenticated remote attacker can manipulate the 4-byte `msg_len` field in a pre-authentication packet. When the `msg_id` is set to `SSH_MSG_KEXINIT`, the library uses this unchecked length to perform a heap allocation via `sshd_zalloc` (which calls `malloc` and `memset`). By sending multiple connections with large `msg_len` values, an attacker can trigger the system's Out-Of-Memory (OOM) killer to terminate the server process. A patch (commit 3f9f0c6) introduces `LWS_SSH_MAX_PACKET_SIZE` to enforce a 256KB limit.

Affected products

warmcat libwebsockets up to 4.5.8

Timeline

2026-06-02: advisory: NVD publication date
2026-06-02: disclosed: Vulnerability details and PoC published by researcher
2026-06-02: patched: Patch commit 3f9f0c6ecaf0e6f3f219d30632c5d1f2479d7498 released

References

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