---
id: CVE-2026-61629
title: nginx ignition is a user interface for the nginx web server
summary: >-
  nginx ignition is a user interface for the nginx web server. In versions
  2.29.0 through 2.40.0, the gin i18n middleware in nginx-ignition's API server
  runs in front of every HTTP request and calls
  `golang.org/x/text/language.ParseAcceptL…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: lucasdillmann
product: nginx-ignition
affected:
  - 'nginx-ignition >= 2.29.0, < 2.40.1'
patched:
  - github.com/lucasdillmann/nginx-ignition 0.0.0-20260526022344-0c988fc1277c
published: '2026-09-21'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T18:25:00.707'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61629'
references:
  - url: >-
      https://github.com/lucasdillmann/nginx-ignition/commit/0c988fc1277c7d291725e8373313f8486fa1b31a
    label: security-advisories@github.com
  - url: >-
      https://github.com/lucasdillmann/nginx-ignition/commit/cbaf0fc16ed873f7178a2ca9b0d00a696e44b485
    label: security-advisories@github.com
  - url: >-
      https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61629'
  - url: 'https://github.com/lucasdillmann/nginx-ignition/pull/125'
  - url: 'https://github.com/lucasdillmann/nginx-ignition/releases/tag/2.40.1'
  - url: 'https://github.com/advisories/GHSA-jr34-h97m-9hpx'
  - url: 'https://github.com/lucasdillmann/nginx-ignition'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
  - osv
epss: 0.00358
epssPercentile: 0.29653
aliases:
  - GHSA-jr34-h97m-9hpx
ecosystem: go
ingestedAt: '2026-09-21T14:38:56.369Z'
---

## Overview

nginx ignition is a user interface for the nginx web server. In versions 2.29.0 through 2.40.0, the gin i18n middleware in nginx-ignition's API server runs in front of every HTTP request and calls `golang.org/x/text/language.ParseAcceptLanguage` on the raw `Accept-Language` header without imposing any size or shape filter. The underlying parser has quadratic-time behaviour on long lists of malformed language tags. The CVE-2022-32149 guard that golang.org/x/text added in v0.3.8 caps the number of `-` characters in the input at 1000, but it does not cap `_` characters even though the parser's internal scanner aliases `_` to `-` before parsing. A single unauthenticated GET request with an `Accept-Language` header built out of `_` separators burns about 2.4 seconds of server CPU on the host running nginx-ignition; ten concurrent attackers saturate a ten-core box for the duration of the attack while consuming ~10 MiB/s of upstream bandwidth. Version 2.40.1 fixes this issue.

## Remediation

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

## Package advisory (CVE-2026-61629)

Affected packages:

- `github.com/lucasdillmann/nginx-ignition >= 0.0.0-20260126024607-cbaf0fc16ed8, < 0.0.0-20260526022344-0c988fc1277c`

Patched in:

- `github.com/lucasdillmann/nginx-ignition 0.0.0-20260526022344-0c988fc1277c`

Source: https://github.com/advisories/GHSA-jr34-h97m-9hpx