{"id":"CVE-2026-56434","details":"NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssi_module module. This vulnerability may exist when the Server-Side Includes (SSI), proxy_pass, and proxy_buffering off directives are configured. With this configuration, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to cause a use-after-free in the NGINX worker process. This issue may lead to limited modification of memory or a restart of the NGINX worker process.\n\nImpact:\nThis vulnerability may allow remote attackers to have limited control to modify memory contents or restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only.\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","aliases":["BIT-nginx-2026-56434","BIT-nginx-gateway-2026-56434"],"modified":"2026-08-26T17:12:12.395667840Z","published":"2026-07-15T15:16:45.700Z","related":["ALSA-2026:59216","ALSA-2026:59220","ALSA-2026:59362","ALSA-2026:59490","CGA-v28f-hqh8-xq3r","openSUSE-SU-2026:11295-1"],"database_specific":{"unresolved_ranges":[{"extracted_events":[{"introduced":"3.5.0"},{"last_affected":"3.7.2"},{"introduced":"5.0.0"},{"fixed":"5.5.3"},{"introduced":"2026-lts-r1"},{"fixed":"2026-lts-r4"}],"source":"CPE_RANGE","vendor_product":"f5:nginx_ingress_controller","cpes":["cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*","cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:long-term_support:*:*:*"]},{"cpes":["cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"37.0.0.1"},{"fixed":"37.0.3.1"},{"introduced":"r33"},{"fixed":"r36"}],"source":"CPE_RANGE","vendor_product":"f5:nginx_plus"},{"vendor_product":"f5:waf","cpes":["cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*"],"extracted_events":[{"introduced":"4.11.0"},{"last_affected":"4.16.0"},{"introduced":"5.2.0"},{"last_affected":"5.8.0"},{"introduced":"5.9.0"},{"fixed":"5.13.4"}],"source":"CPE_RANGE"},{"extracted_events":[{"introduced":"4.0.0"},{"last_affected":"4.0.0"},{"introduced":"4.0.1"},{"last_affected":"4.0.1"}],"source":"CPE_STRING","vendor_product":"f5:nginx_ingress_controller","cpes":["cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:continuous_releases:*:*:*","cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:continuous_releases:*:*:*"]},{"extracted_events":[{"introduced":"r36-NA"},{"last_affected":"r36-NA"},{"introduced":"r36-p1"},{"last_affected":"r36-p1"},{"introduced":"r36-p2"},{"last_affected":"r36-p2"},{"introduced":"r36-p3"},{"last_affected":"r36-p3"},{"introduced":"r36-p4"},{"last_affected":"r36-p4"},{"introduced":"r36-p5"},{"last_affected":"r36-p5"},{"introduced":"r36-p6"},{"last_affected":"r36-p6"}],"source":"CPE_STRING","vendor_product":"f5:nginx_plus","cpes":["cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:*","cpe:2.3:a:f5:nginx_plus:r36:p6:*:*:*:*:*:*"]}]},"references":[{"type":"ADVISORY","url":"https://my.f5.com/manage/s/article/K000162098"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nginx/nginx-gateway-fabric","events":[{"introduced":"3a372747333fb1db372af7cf0b18ed7eef7c91f7"},{"last_affected":"532db6a20b2912fe397211eef9f8d564d46a4bdd"},{"introduced":"7dad8b31e3f0c3eadce36fed8c276e83e6583d24"},{"fixed":"5e34a17a8f7787e90f41d1af91258a556f0795b4"}],"database_specific":{"cpe":"cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"1.3.0"},{"last_affected":"1.6.2"},{"introduced":"2.0.0"},{"fixed":"2.6.7"}],"source":"CPE_RANGE"}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56434.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}