Vulnerability in GNOME Libsoup
CVE-2026-3634
A flaw was found in libsoup. An attacker controlling the value used to set the Content-Type header can inject a Carriage Return Line Feed (CRLF) sequence due to improper input sanitization in the `soup_message_headers_set_content_type()` function. This vulnerability allows for the injection of arbitrary header-value pairs, potentially leading to HTTP header injection and response splitting attacks.
Vulnerability class: CRLF Injection
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (21.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 21.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-3634 (vdb-entry, Vendor Advisory)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Issue Tracking, Vendor Advisory)
- gitlab.gnome.org/GNOME/libsoup/-/issues/485 (Exploit, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-3634?
- CVE-2026-3634 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-2026-3634?
- Low severity. CVSS v3 base score is 3.9 out of 10.