lucasdillmann nginx-ignition up to 2.40.0 i18n middleware golang.org/x/text/language.ParseAcceptLanguage resource consumption

Summaryinfo

A vulnerability classified as problematic has been found in lucasdillmann nginx-ignition up to 2.40.0. Impacted is the function golang.org/x/text/language.ParseAcceptLanguage of the component i18n middleware. This manipulation causes resource consumption. This vulnerability is tracked as CVE-2026-61629. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in lucasdillmann nginx-ignition up to 2.40.0 and classified as problematic. Affected by this vulnerability is the function golang.org/x/text/language.ParseAcceptLanguage of the component i18n middleware. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-61629 since 07/10/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 2.40.1 eliminates this vulnerability.

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Productinfo

Type

• Web Server

Vendor

• lucasdillmann

Name

• nginx-ignition

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.36
• 2.37
• 2.38
• 2.39
• 2.40.0

Website

• Product: https://github.com/lucasdillmann/nginx-ignition/

CPE 2.3info

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