---
id: CVE-2026-6324
title: >-
  Libsoup: libsoup: http request smuggling via unsigned to signed conversion
  error
summary: >-
  A flaw was found in libsoup. A remote attacker could exploit an unsigned to
  signed conversion error in the `soup_body_input_stream_read_chunked()`
  function by sending a malicious HTTP request. This vulnerability occurs when
  libsoup opera…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-444
vendor: Red Hat
product: libsoup3
affected:
  - libsoup3 (all versions)
  - libsoup (all versions)
  - libsoup (all versions)
  - libsoup (all versions)
  - libsoup (all versions)
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-05-29T14:00:40.782194Z'
exploitAvailable: true
published: '2026-05-29'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:51:04.201Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-6324'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-6324'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2458479'
    label: RHBZ#2458479
  - url: >-
      https://gitlab.gnome.org/GNOME/libsoup/-/commit/96ac392b444d01bd5de1d1276b187c3ed49d048c
  - url: 'https://gitlab.gnome.org/GNOME/libsoup/-/issues/508'
tags:
  - cve.org
  - exploit-available
epss: 0.00872
epssPercentile: 0.59038
ingestedAt: '2026-11-05T19:30:42.888Z'
---

## Overview

A flaw was found in libsoup. A remote attacker could exploit an unsigned to signed conversion error in the `soup_body_input_stream_read_chunked()` function by sending a malicious HTTP request. This vulnerability occurs when libsoup operates behind a non-libsoup proxy server or as a proxy in front of a non-libsoup backend server. Successful exploitation can allow an attacker to bypass security controls, poison web caches, or gain unauthorized access.

## Affected

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

## Remediation

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