CVE-2026-42530: NGINX Open-Source ngx_http_v3_module vulnerability
NGINX Open Source has a vulnerability in the ngxhttpv3module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42530?
The severity of CVE-2026-42530 is rated as critical with a CVSS score of 9.2.
How do I fix CVE-2026-42530?
To fix CVE-2026-42530, update your NGINX Open Source installation to the latest patched version that addresses the vulnerability.
What are the potential impacts of CVE-2026-42530?
CVE-2026-42530 allows a remote unauthenticated attacker to exploit the vulnerability, potentially leading to unauthorized access or service disruption.
Which versions of NGINX are affected by CVE-2026-42530?
CVE-2026-42530 affects NGINX Open Source configured to use the HTTP/3 QUIC module.
What type of vulnerability is CVE-2026-42530 classified as?
CVE-2026-42530 is classified as a 'Use After Free' vulnerability.