{"id":"CVE-2026-42055","title":"NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules","summary":"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, …","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-122","CWE-787","CWE-131"],"vendor":"f5","product":"dos","affected":["dos >= 4.3.0, <= 4.7.0","dos = 4.9.0","nginx_gateway_fabric >= 1.3.0, <= 1.6.2","nginx_gateway_fabric >= 2.0.0, <= 2.6.3","nginx_ingress_controller >= 3.5.0, <= 3.7.2","nginx_ingress_controller >= 4.0.0, <= 4.0.1","nginx_ingress_controller >= 5.0.0, <= 5.5.0","nginx_instance_manager >= 2.17.0, <= 2.22.0","nginx_open_source >= 1.0.0, <= 1.30.2","nginx_open_source >= 1.31.0, <= 1.31.1","nginx_plus >= 37.0.0.1, < 37.0.2.1","nginx_plus >= r33, < r36","nginx_plus = r36","waf >= 4.10.0, <= 4.16.0","waf >= 5.2.0, <= 5.8.0","waf >= 5.9.0, <= 5.13.1","discovery","hardened_images","update_infrastructure >= 5.0, < 5.2","enterprise_linux = 8.0","enterprise_linux = 9.0","enterprise_linux = 10.0"],"patched":["nginx_plus r36","update_infrastructure 5.2"],"published":"2026-06-17","updated":"2026-09-14","sourceUpdated":"2026-09-14T13:18:34.690","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-42055","references":[{"url":"https://my.f5.com/manage/s/article/K000161584","label":"f5sirt@f5.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:27197","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36331","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36364","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36618","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:36639","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:38847","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:44481","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:46836","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:58981","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-42055","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2489866","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd","cve.org","exploit-available"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-06-17T00:00:00+00:00"},"epss":0.02355,"epssPercentile":0.82998,"exploits":{"github":1,"githubRepos":["https://github.com/HORKimhab/CVE-2026-42055"],"checkedAt":"2026-09-25T08:20:56.917Z"},"exploitAvailable":true,"ingestedAt":"2026-07-03T13:02:27.787Z","slug":"CVE-2026-42055","body":"## Overview\n\nNGINX 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.\n\n## Affected\n\n- `dos >= 4.3.0, <= 4.7.0`\n- `dos = 4.9.0`\n- `nginx_gateway_fabric >= 1.3.0, <= 1.6.2`\n- `nginx_gateway_fabric >= 2.0.0, <= 2.6.3`\n- `nginx_ingress_controller >= 3.5.0, <= 3.7.2`\n- `nginx_ingress_controller >= 4.0.0, <= 4.0.1`\n- `nginx_ingress_controller >= 5.0.0, <= 5.5.0`\n- `nginx_instance_manager >= 2.17.0, <= 2.22.0`\n- `nginx_open_source >= 1.0.0, <= 1.30.2`\n- `nginx_open_source >= 1.31.0, <= 1.31.1`\n- `nginx_plus >= 37.0.0.1, < 37.0.2.1`\n- `nginx_plus >= r33, < r36`\n- `nginx_plus = r36`\n- `waf >= 4.10.0, <= 4.16.0`\n- `waf >= 5.2.0, <= 5.8.0`\n- `waf >= 5.9.0, <= 5.13.1`\n- `discovery`\n- `hardened_images`\n- `update_infrastructure >= 5.0, < 5.2`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n- `enterprise_linux = 10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `nginx_plus r36`\n- `update_infrastructure 5.2`","depth":"midnight","depthScore":57,"depthScoreParts":{"impact":44.6,"likelihood":0.5,"exploitation":12,"ransomware":0},"changes":[{"seq":5190,"id":"CVE-2026-42055","ts":1788887253205,"field":"exploit_available","old":"false","new":"true"},{"seq":4073,"id":"CVE-2026-42055","ts":1788886369058,"field":"exploit_available","old":"true","new":"false"},{"seq":2862,"id":"CVE-2026-42055","ts":1788883035101,"field":"exploit_available","old":"false","new":"true"},{"seq":1891,"id":"CVE-2026-42055","ts":1788882438512,"field":"exploit_available","old":"true","new":"false"},{"seq":988,"id":"CVE-2026-42055","ts":1788881872644,"field":"exploit_available","old":"false","new":"true"}]}