---
id: CVE-2026-15176
title: >-
  A vulnerability exists in NGINX Plus and NGINX Open Source when a location is
  configured that uses the alias directive together with rewrite and a set or
  return directive referencing the $request_filename variable
summary: >-
  A vulnerability exists in NGINX Plus and NGINX Open Source when a location is
  configured that uses the alias directive together with rewrite and a set or
  return directive referencing the $request_filename variable. Alternatively,
  the sam…
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
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T16:04:11.750'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-15176'
references:
  - url: 'https://my.f5.com/manage/s/article/K000162416'
    label: f5sirt@f5.com
tags:
  - nvd
ingestedAt: '2026-10-14T15:36:14.018Z'
---

## Overview

A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the alias directive together with rewrite and a set or return directive referencing the $request_filename variable. Alternatively, the same result could be achieved when the $request_filename variable is used in an access log format directive. 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.