Vulnerability in Gnome Libsoup

CVE-2026-3633

A flaw was found in libsoup. A remote attacker, by controlling the method parameter of the `soup_message_new()` function, could inject arbitrary headers and additional request data. This vulnerability, known as CRLF (Carriage Return Line Feed) injection, occurs because the method value is not properly escaped during request line construction, potentially leading to HTTP request injection.

Vulnerability class: CRLF Injection

EPSS: 0.002 (13.1th 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-2026-3633?
CVE-2026-3633 is a low-severity vulnerability in Gnome Libsoup, classified under CRLF Injection. CVSS score: 3.9/10. Published 2026-03-17.
How severe is CVE-2026-3633?
Low severity. CVSS v3 base score is 3.9 out of 10.