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libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. (CVE-2026-19773)

0
Critical
Published: 09/15/2026 (09/15/2026, 21:31:15 UTC)
Source: GCVE Database

Description

CVE-2026-19773 is a critical remote code execution vulnerability in libwebsockets affecting the HTTP/2 HPACK path header parsing. It allows unauthenticated remote attackers to execute arbitrary code due to an out-of-bounds write caused by improper validation of user-supplied data during header parsing.

CVSS v3.0

Score 9.8critical

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/16/2026, 03:33:12 UTC

Technical Analysis

This vulnerability in libwebsockets arises from a lack of proper validation in the HTTP/2 HPACK path header parsing logic, leading to an out-of-bounds write condition. An attacker can exploit this flaw to execute arbitrary code within the context of the affected process without requiring authentication. The CVSS v3.0 base score is 9.8, indicating critical severity with network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.

Potential Impact

Successful exploitation allows remote attackers to execute arbitrary code on affected systems, potentially leading to full compromise of the process running libwebsockets. No authentication is required, increasing the risk of exploitation. The vulnerability affects confidentiality, integrity, and availability of the affected system.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Until a patch is available, consider mitigating exposure by restricting access to services using libwebsockets or employing network-level protections.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
GHSA-r4m8-276f-3r2f
Osv Schema Version
1.4.0
Aliases
["CVE-2026-19773"]
Database Specific Severity
CRITICAL
Cvss Version
3.0

Threat ID: 6aaa080455bf5e2cf5ea47ea

Added to database: 09/16/2026, 03:07:48 UTC

Last enriched: 09/16/2026, 03:33:12 UTC

Last updated: 09/16/2026, 04:21:26 UTC

Views: 2

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