CVE-2026-42533

9.2 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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

A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap 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.

Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. 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/K000162097

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-2026-42533.json"