CVE-2026-3632

Libsoup: libsoup: http smuggling and server-side request forgery via malformed hostnames

MEDIUM
5.5
CVSS Score
Published: March 17, 2026 at 09:44 AM UTC
Updated: June 17, 2026 at 10:43 AM UTC
2 products affected across 2 vendorsEnterprise LinuxLibsoup

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
Vendor states this is fixed in 6 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

VDB Entryx_refsource_REDHATVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-3632
Issue Trackingx_refsource_REDHATVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2445127
ExploitIssue TrackingVendor Advisory
Source: cverecord
https://gitlab.gnome.org/GNOME/libsoup/-/issues/483

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-1286

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