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CVE

CVE-2026-19773

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

CVE-2026-19773

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

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.8
-
3.0
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
9.8
-
3.0
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19773.json, https://github.com/warmcat/libwebsockets/commit/824151862f37bc72f46d9a3e01d5b9408d313a0b, https://nvd.nist.gov/vuln/detail/CVE-2026-19773, https://www.zerodayinitiative.com/advisories/ZDI-26-590/

Severity

9.8

CVSS Score
0
10

Basic Information

Base CVSS
9.8
EPSS Probability
0.00646%
EPSS Percentile
0.49495%
Introduced Version
b4b5aed3903eaff09cd76a410f69bbe5dff66f8e,0
Fix Available
824151862f37bc72f46d9a3e01d5b9408d313a0b,4.3.5-1+deb13u3,4.3.5-3ubuntu1.2+esm1,2.0.3-3ubuntu0.1~esm1,3.2.1-3ubuntu0.1~esm3,4.3.3-1.1ubuntu0.1~esm3,4.0.20-2ubuntu1.1+esm2

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