CVE-2025-4035 MEDIUM

CVE-2025-4035: Libsoup: cookie domain validation bypass via uppercase characters in libsoup

Vendor Red Hat
Product Red Hat Enterprise Linux 6
Weakness CWE-178
Published April 29, 2025
Last update November 18, 2025

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

A flaw was found in libsoup. When handling cookies, libsoup clients mistakenly allow cookies to be set for public suffix domains if the domain contains at least two components and includes an uppercase character. This bypasses public suffix protections and could allow a malicious website to set cookies for domains it does not own, potentially leading to integrity issues such as session fixation.

Key dates

02Disclosure timeline

April 29, 2025 CVE published
November 18, 2025 Record updated