CVE-2026-56434

8.3 (High) CVSS_V4 - 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 CVSS Calculator

Summary

[none]

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.

Impact: This 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.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Database specific

{
    "unresolved_ranges": [
        {
            "cpes": [
                "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*",
                "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:long-term_support:*:*:*"
            ],
            "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_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"
        },
        {
            "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",
            "vendor_product": "f5:waf"
        },
        {
            "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": "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_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:*:*:*:*:*:*"
            ],
            "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"
        }
    ]
}

References

https://my.f5.com/manage/s/article/K000162098

Affected packages

Git / github.com/nginx/nginx-gateway-fabric

Affected ranges

Type

GIT

Repo

https://github.com/nginx/nginx-gateway-fabric

Events

Introduced

3a372747333fb1db372af7cf0b18ed7eef7c91f7

Last Affected

532db6a20b2912fe397211eef9f8d564d46a4bdd

Introduced

7dad8b31e3f0c3eadce36fed8c276e83e6583d24

Fixed

5e34a17a8f7787e90f41d1af91258a556f0795b4

Database specific

Show details

{
    "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"