Ubuntu 26.04 LTS nginx Denial of Service Vulnerability Disclosed
Severity: Medium (Score: 45.8)
Sources: launchpad.net, Linuxsecurity, Ubuntu
Published: · Updated:
Keywords: ubuntu, nginx, issue, made, consume, excessive, denial
Severity indicators: issue, rce
Summary
A vulnerability in nginx affects multiple versions of Ubuntu, including 26.04 LTS, 25.10, 24.04 LTS, and 22.04 LTS. The issue arises from improper handling of cookie headers in the HTTP/2 implementation, allowing remote attackers to exploit it via specially crafted network traffic. This could lead to excessive resource consumption and result in a denial of service. Users are advised to update their systems to specific package versions to mitigate the risk. The vulnerability has been assigned USN-8398-1, and a standard system update will apply the necessary changes. No active exploitation has been reported at this time. Key Points: • nginx vulnerability affects Ubuntu 26.04 LTS and earlier versions. • Attackers can exploit the flaw through specially crafted HTTP/2 traffic. • Users should update to specified package versions to prevent denial of service.
Detailed Analysis
**Impact** This vulnerability affects multiple Ubuntu releases and their derivatives, specifically Ubuntu 22.04 LTS, 24.04 LTS, 25.10, and 26.04 LTS, impacting any organization using nginx on these platforms. The issue allows remote attackers to cause a denial of service by exhausting server resources, potentially disrupting web services and impacting business operations reliant on affected servers. No specific sectors, geographies, or data compromise details are provided. **Technical Details** The vulnerability arises from improper handling of certain cookie headers in the HTTP/2 implementation of nginx, enabling remote attackers to trigger excessive resource consumption. No CVE identifier is mentioned in the sources. The attack vector is network-based, exploiting malformed HTTP/2 traffic to induce denial of service. No malware, tools, or infrastructure details are provided, nor are any indicators of compromise (IOCs) specified. **Recommended Response** Apply the updated nginx packages provided by Ubuntu for each affected release immediately: versions 1.28.3-2ubuntu1.3 for Ubuntu 26.04 LTS, 1.28.0-6ubuntu1.5 for Ubuntu 25.10, 1.24.0-2ubuntu7.10 for Ubuntu 24.04 LTS, and 1.18.0-6ubuntu14.13 for Ubuntu 22.04 LTS. Conduct standard system updates to ensure all necessary patches are applied. Monitor network traffic for unusual HTTP/2 cookie header patterns indicative of exploitation attempts. No additional detection or mitigation details are available.
Source articles (3)
- USN-8398-1: nginx vulnerability — Ubuntu · 2026-06-08
nginx could be made to consume excessive resources if it received specially crafted network traffic. It was discovered that nginx incorrectly handled certain cookie headers in the HTTP/2 implementatio… - 1.18.0-6ubuntu14.13 — launchpad.net · 2026-06-08
The nginx_http_auth_pam module enables authentication using PAM. . The module uses PAM as a backend for simple http authentication. It also allows setting the pam service name to allow more fine grain… - Ubuntu 26.04 LTS nginx Denial of Service Resource Issue Vuln USN-8398 — Linuxsecurity · 2026-06-08
A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 26.04 LTS - Ubuntu 25.10 - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS Summary: nginx could be made to consume excessive resourc…
Timeline
- 2026-06-08 — USN-8398-1 vulnerability disclosed: A vulnerability in nginx was announced, affecting multiple Ubuntu releases due to improper cookie header handling.
- 2026-06-08 — Ubuntu security notice issued: Ubuntu published a security notice detailing the nginx vulnerability and recommended updates for affected systems.
Related entities
- DDoS (Attack Type)
- Denial of Service (Attack Type)
- Ubuntu (Company)
- Nginx (Tool)