Vulnerability · Published May 29, 2026 · Assigned by redhat

CVE-2026-6324Libsoup: libsoup: http request smuggling via unsigned to signed conversion error

Medium 4.8

In plain English

A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 59% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.9%top 40.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libsoup2.4no fix listedDEBIAN-CVE-2026-6324
Debian:13libsoup2.4no fix listedDEBIAN-CVE-2026-6324
Debian:12libsoup3no fix listedDEBIAN-CVE-2026-6324
Debian:13libsoup3no fix listedDEBIAN-CVE-2026-6324
Ubuntu:22.04:LTSlibsoup2.42.74.2-3ubuntu0.9USN-8890-1
Ubuntu:22.04:LTSlibsoup2.4no fix listedUBUNTU-CVE-2026-6324
Ubuntu:24.04:LTSlibsoup2.4no fix listedUBUNTU-CVE-2026-6324
Ubuntu:24.04:LTSlibsoup2.42.74.3-6ubuntu1.9USN-8890-1
Ubuntu:25.10libsoup2.4no fix listedUBUNTU-CVE-2026-6324
Ubuntu:26.04:LTSlibsoup2.4no fix listedUBUNTU-CVE-2026-6324
Ubuntu:26.10libsoup2.4no fix listedUBUNTU-CVE-2026-6324
Ubuntu:24.04:LTSlibsoup33.4.4-5ubuntu0.9UBUNTU-CVE-2026-6324
Ubuntu:24.04:LTSlibsoup33.4.4-5ubuntu0.9USN-8890-1
Ubuntu:25.10libsoup3no fix listedUBUNTU-CVE-2026-6324
Ubuntu:26.04:LTSlibsoup33.6.6-1ubuntu0.1USN-8890-1
Ubuntu:26.04:LTSlibsoup33.6.6-1ubuntu0.1UBUNTU-CVE-2026-6324
Ubuntu:26.10libsoup33.6.6-1ubuntu3USN-8890-2
Ubuntu:26.10libsoup33.6.6-1ubuntu3UBUNTU-CVE-2026-6324

Affected products (as reported)

Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

References