CVE-2026-19773
libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability
- State
- Published
- Severity
- 9.8 Critical
- Published
- Sep 15, 2026
- Updated
- Sep 16, 2026
- Reserved
- Aug 13, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.0 | 9.8 Critical | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | zdi |
Weaknesses
- CWE-787 Out-of-bounds Write
Affected Products
| Product | Versions |
|---|---|
libwebsocketslibwebsockets |
|
References
- ZDI-26-590
- vendor-provided URLvendor-advisory
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