Vulnerability in Gnome Libsoup

CVE-2026-3632

A flaw was found in libsoup, a library used by applications to send network requests. This vulnerability occurs because libsoup does not properly validate hostnames, allowing special characters to be injected into HTTP headers. A remote attacker could exploit this to perform HTTP smuggling, where they can send hidden, malicious requests alongside legitimate ones. In certain situations, this could lead to Server-Side Request Forgery (SSRF), enabling an attacker to force the server to make unauthorized requests to other internal or external systems. The impact is low, as SoupServer is not actually used in internet infrastructure.

EPSS: 0.002 (11.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.9 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3632?
CVE-2026-3632 is a low-severity vulnerability in Gnome Libsoup, classified under CWE-1286. CVSS score: 3.9/10. Published 2026-03-17.
How severe is CVE-2026-3632?
Low severity. CVSS v3 base score is 3.9 out of 10.