Use After Free Affecting libsoup3 package, versions <3.6.6-1ubuntu0.1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.83% (57th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UBUNTU2604-LIBSOUP3-16235586
  • published1 Oct 2026
  • disclosed17 Mar 2026

Introduced: 17 Mar 2026

CVE-2026-4271  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Ubuntu:26.04 libsoup3 to version 3.6.6-1ubuntu0.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libsoup3 package and not the libsoup3 package as distributed by Ubuntu. See How to fix? for Ubuntu:26.04 relevant fixed versions and status.

A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).

CVSS Base Scores

version 3.1