HTTP Request Smuggling Affecting libsoup-debugsource package, versions <0:2.72.0-6.amzn2023.0.16


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.25% (15th 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-AMZN2023-LIBSOUPDEBUGSOURCE-20873431
  • published13 Oct 2026
  • disclosed30 Sept 2026

Introduced: 30 Sep 2026

NewCVE-2026-103399  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 libsoup-debugsource to version 0:2.72.0-6.amzn2023.0.16 or higher.
This issue was patched in ALAS2023-2026-3212.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libsoup-debugsource package and not the libsoup-debugsource package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the declared body bytes nor closes the connection. On a keep-alive connection, those leftover bytes are interpreted as a subsequent HTTP request. A remote, unauthenticated attacker can place a complete HTTP request in the body and cause SoupServer to process that smuggled request, leading to unintended request handling.

CVSS Base Scores

version 3.1