HTTP Request Smuggling Affecting libsoup2.4 package, versions *


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.28% (18th percentile)

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  • Snyk IDSNYK-UBUNTU2404-LIBSOUP24-18323187
  • published1 Oct 2026
  • disclosed24 Jul 2026

Introduced: 24 Jul 2026

CVE-2026-66338  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

There is no fixed version for Ubuntu:24.04 libsoup2.4.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libsoup2.4 package and not the libsoup2.4 package as distributed by Ubuntu. See How to fix? for Ubuntu:24.04 relevant fixed versions and status.

A flaw was found in libsoup. The chunked transfer encoding parser uses a permissive parsing function for chunk sizes that silently accepts inputs violating RFC 9112, including leading whitespace, plus sign prefixes, and trailing invalid characters. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP requests.

CVSS Base Scores

version 3.1