libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. (CVE-2026-19773)
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.
AI Analysis
Technical Summary
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.
libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. (CVE-2026-19773)
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
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
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.
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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