๐Ÿ” CVE Alert

CVE-2026-19773

CRITICAL 9.8

libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability

CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th

libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of libwebsockets. Authentication is not required to exploit this vulnerability. The specific flaw exists within the parsing of HTTP/2 HPACK path header. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-31036.

CWE CWE-787
Vendor libwebsockets
Product libwebsockets
Published Sep 15, 2026
Last Updated Sep 15, 2026
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CVSS v3 Breakdown

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Versions

libwebsockets / libwebsockets
b4b5aed3903eaff09cd76a410f69bbe5dff66f8e

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
zerodayinitiative.com: https://www.zerodayinitiative.com/advisories/ZDI-26-590/ github.com: https://github.com/warmcat/libwebsockets/commit/824151862f37bc72f46d9a3e01d5b9408d313a0b