---
id: CVE-2026-3634
title: >-
  Libsoup: libsoup: http header injection and response splitting via crlf
  injection in content-type header
summary: >-
  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()`…
severity: low
cvss: 3.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-93
vendor: Red Hat
product: libsoup3
affected:
  - libsoup3 (all versions)
  - libsoup
  - libsoup (all versions)
  - libsoup (all versions)
  - libsoup (all versions)
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-03-17T13:03:02.939035Z'
exploitAvailable: true
published: '2026-03-17'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:24:11.360Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-3634'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-3634'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2445129'
    label: RHBZ#2445129
  - url: 'https://gitlab.gnome.org/GNOME/libsoup/-/issues/485'
tags:
  - cve.org
  - exploit-available
epss: 0.00195
epssPercentile: 0.09338
ingestedAt: '2026-11-05T19:30:42.888Z'
---

## Overview

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.

## Affected

- `libsoup3 (all versions)`
- `libsoup`
- `libsoup (all versions)`
- `libsoup (all versions)`
- `libsoup (all versions)`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.