---
schema_version: '1.0'
id: security-20260719-3eea23
url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-42533
url_hash: 3eea2367f3ebe1c3952249e546b7b2117de4b80d01919dd27da2b8ed53c0ac7d
canonical_url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-42533
source: osv:debian
category: security/os
category_raw: cve/os
region: null
tags:
- cve
- DEBIAN-CVE-2026-42533
- severity: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
- nginx
- Debian
lang: en
published_at: '2026-07-15T15:16:33Z'
fetched_at: '2026-07-19T06:51:51.697110Z'
updated_at: '2026-07-19T06:52:16Z'
status: published
content_hash: adced11fcf624d555ed668c117de94959f01e31934e3c88e0778f2077d1cc5ca
content_changed_at: null
license_note: full
summary: 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-cac
summary_source: rss
summary_en: 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-cac
entities:
- name: CVE
  type: concept
key_facts: []
related: []
related_auto:
- name: MCP_Python_SDK
  type: content
  weight: 2.0
title: DEBIAN-CVE-2026-42533 — nginx
---

# DEBIAN-CVE-2026-42533 — nginx

## TL;DR
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-cac

## Key Points
- cve / DEBIAN-CVE-2026-42533 / severity: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 / nginx / Debian

## Details
**Severity:** 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
**Advisory:** DEBIAN-CVE-2026-42533

**Affected (your watchlist):**
- `Debian:nginx` 1.22.1-9+deb12u1 → no fixed version listed [proxmox]

**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.

**References:**
- https://security-tracker.debian.org/tracker/CVE-2026-42533

_Data: OSV.dev (upstream: debian) — https://osv.dev/vulnerability/DEBIAN-CVE-2026-42533_

## Source
元記事: [DEBIAN-CVE-2026-42533 — nginx](https://osv.dev/vulnerability/DEBIAN-CVE-2026-42533) — published 2026-07-15T15:16:33Z