{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-42055: NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-42055","status":"final","version":"1","initial_release_date":"2026-06-17T14:04:32.520Z","current_release_date":"2026-06-17T15:43:16.661Z","revision_history":[{"date":"2026-06-17T14:04:32.520Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"NGINX 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. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-42055 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-42055"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-42055"},{"category":"external","summary":"my.f5.com","url":"https://my.f5.com/manage/s/article/K000161584"}]},"product_tree":{"branches":[{"category":"vendor","name":"F5","branches":[{"category":"product_name","name":"NGINX Open Source","branches":[{"category":"product_version_range","name":">=1.13.10 <1.31.2","product":{"name":"F5 NGINX Open Source >=1.13.10 <1.31.2","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=1.30.2 <1.30.3","product":{"name":"F5 NGINX Open Source >=1.30.2 <1.30.3","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*"}}}]}]},{"category":"vendor","name":"F5","branches":[{"category":"product_name","name":"NGINX Plus","branches":[{"category":"product_version_range","name":">=37.0 <37.0.2.1","product":{"name":"F5 NGINX Plus >=37.0 <37.0.2.1","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=R36 <R36 P6","product":{"name":"F5 NGINX Plus >=R36 <R36 P6","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-42055","title":"NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability","notes":[{"category":"description","text":"NGINX 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. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","baseScore":9.2,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 1.30.3, 1.31.2, 37.0.2.1, R36 P6.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"]}]}]}