Libwebsockets

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.

Published: 2026-06-02T21:15:10.566Z
Updated: 2026-06-03T14:04:31.919Z

Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows Pointer Manipulation, potentially leading to out-of-bounds memory access. This issue affects libwebsockets before 4.3.4 and is present in code built specifically for the Win32 platform. By default, the affected code is not executed unless one of the following conditions is met: LWS_WITHOUT_EXTENSIONS (default ON) is manually set to OFF in CMake. LWS_WITH_HTTP_STREAM_COMPRESSION (default OFF) is manually set to ON in CMake. Despite these conditions, when triggered in affected configurations, this vulnerability may allow attackers to manipulate pointers, potentially leading to memory corruption or unexpected behavior.

Published: 2025-03-03T08:44:23.118Z
Updated: 2025-03-03T16:34:59.877Z

Out-of-bounds Write in unfilter_scanline in warmcat libwebsockets allows, when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display stack is used, to write past a heap allocated buffer possibly causing a crash, when the user visits an attacker controlled website that contains a crafted PNG file with a big width value that causes an integer overflow which value is used for determining the size of a heap allocation.

Published: 2025-10-20T14:04:06.854Z
Updated: 2025-10-20T14:34:57.848Z

Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets allows, when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display stack is used, to read past a heap allocated buffer possibly causing a crash, when the user visits an attacker controlled website that contains a crafted PNG file with a big height dimension.

Published: 2025-10-20T13:58:31.286Z
Updated: 2025-10-20T14:03:41.592Z

Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

Published: 2025-10-20T13:41:10.787Z
Updated: 2025-10-24T10:54:30.961Z