A vulnerability was found in warmcat libwebsockets 4.5.0. Impacted is the function report_raw_cbor of the file lib/misc/lecp.c of the component LECP CBOR Recording. The manipulation results in out-of-bounds write. The attack can be launched remotely. The exploit has been made public and could be used. The patch is identified as 1d44554a1bb262db63ff4e240152a9deecd99054. It is best practice to apply a patch to resolve this issue.

A critical out-of-bounds write vulnerability was discovered in warmcat libwebsockets version 4.5.0. The flaw exists in the function report_raw_cbor within lib/misc/lecp.c, part of the LECP CBOR Recording component. The vulnerability can be exploited remotely, allowing attackers to perform out-of-bounds memory writes. A public proof-of-concept exploit has been released, increasing the risk of active exploitation. A patch has been identified via commit 1d44554a1bb262db63ff4e240152a9deecd99054 in the official repository. Users are strongly advised to apply the patch immediately. The vulnerability was publicly disclosed and tracked under CVE-2026-78161.