---
id: CVE-2026-93479
title: >-
  A vulnerability exists in NGINX Plus and NGINX Open Source when a map
  directive uses regex matching and the root directive or access log format
  references the map's regex capture variables before referencing the map output
  variable
summary: >-
  A vulnerability exists in NGINX Plus and NGINX Open Source when a map
  directive uses regex matching and the root directive or access log format
  references the map's regex capture variables before referencing the map output
  variable. Alte…
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
vendor: F5
product: NGINX Plus
affected:
  - nginx_plus >= 37.1.0 < 37.1.0.1
  - nginx_plus >= 37.0.0 < 37.0.5.1
  - nginx_plus >= R36 < *
  - nginx_plus >= R35 < *
  - nginx_plus >= R34 < *
  - nginx_plus >= R33 < *
  - nginx_open_source >= 1.31.2 < 1.31.7
  - nginx_open_source >= 1.30.0 < 1.30.6
published: '2026-10-14'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T11:18:08.093'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93479'
references:
  - url: 'https://my.f5.com/manage/s/article/K000162607'
    label: f5sirt@f5.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T03:57:00.464550Z'
ingestedAt: '2026-10-14T15:36:14.033Z'
---

## Overview

A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format 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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.