{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-42055","assignerOrgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","state":"PUBLISHED","assignerShortName":"f5","dateReserved":"2026-06-02T21:45:04.818Z","datePublished":"2026-06-17T14:04:32.520Z","dateUpdated":"2026-06-18T03:57:46.697Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unknown","modules":["ngx_http_proxy_v2_module","ngx_http_grpc_module"],"product":"NGINX Open Source","vendor":"F5","versions":[{"lessThan":"1.31.2","status":"affected","version":"1.13.10","versionType":"custom"},{"lessThan":"1.30.3","status":"affected","version":"1.30.2","versionType":"custom"}]},{"defaultStatus":"unaffected","modules":["ngx_http_proxy_v2_module","ngx_http_grpc_module"],"product":"NGINX Plus","vendor":"F5","versions":[{"lessThan":"37.0.2.1","status":"affected","version":"37.0","versionType":"custom"},{"lessThan":"R36 P6","status":"affected","version":"R36","versionType":"custom"}]}],"credits":[{"lang":"en","type":"reporter","value":"\"F5 acknowledges Mufeed VH of Winfunc Research, Trung Nguyen (@everping) of CyStack, Feng Xue and XGPT of ThreatBook, Hcamael and 章鱼哥 of aipyapp, and Zhen Yan (AntAISecurityLab) for bringing this issue to our attention and following the highest standards of coordinated disclosure.\""}],"datePublic":"2026-06-17T14:00:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<span style=\"background-color: rgb(255, 255, 255);\">NGINX Plus and NGINX Open Source have a vulnerability in the </span><strong>ngx_http_proxy_v2_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;and </span><strong>ngx_http_grpc_module</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;modules. This vulnerability exists when the </span><strong>proxy_http_version to 2</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;or </span><strong>grpc_pass</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directives are used to proxy HTTP/2 traffic, the </span><strong>ignore_invalid_headers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;directive is set to off, and the </span><strong>large_client_header_buffers</strong><span style=\"background-color: rgb(255, 255, 255);\">&nbsp;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.</span> \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}],"value":"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."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"HIGH","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":9.2,"baseSeverity":"CRITICAL","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","description":"CWE-122 Heap-based Buffer Overflow","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","shortName":"f5","dateUpdated":"2026-06-17T14:04:32.520Z"},"references":[{"tags":["vendor-advisory"],"url":"https://my.f5.com/manage/s/article/K000161584"}],"source":{"discovery":"EXTERNAL"},"tags":["x_F5"],"title":"NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability","x_generator":{"engine":"F5 SIRTBot v1.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-17T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-42055"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-18T03:57:46.697Z"}}]}}