HTTP Request Smuggling Affecting libsoup3 package, versions <3.6.5-7


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.54% (44th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-LIBSOUP3-14399223
  • published12 Dec 2025
  • disclosed11 Dec 2025

Introduced: 11 Dec 2025

CVE-2025-14523  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade Debian:unstable libsoup3 to version 3.6.5-7 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 Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers.

CVSS Base Scores

version 3.1