CVE-2026-19773

critical · 9.8

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.

9.8

CVSS

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EPSS (exploit prob.)

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EPSS percentile

2026-09-15

Published

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

Weaknesses

CWE-787

References

https://github.com/warmcat/libwebsockets/commit/824151862f37bc72f46d9a3e01d5b9408d313a0b
https://www.zerodayinitiative.com/advisories/ZDI-26-590/

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-19773