23 Oct 2026 15:48:27 UTC
NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
cve-program · CVE-2026-42055 · Published
CVE-2026-42055
NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
CVSS 3.1 8.1 HIGHCVSS 4.0 9.2 CRITICALCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-42055
PublishedNGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow 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.
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