CVE-2025-4948

A flaw was found in the soup_multipart_new_from_message() function of the libsoup HTTP library, which is commonly used by GNOME and other applications to handle web communications. The issue occurs when the library processes specially crafted multipart messages. Due to improper validation, an internal calculation can go wrong, leading to an integer underflow. This can cause the program to access invalid memory and crash. As a result, any application or server using libsoup could be forced to exit unexpectedly, creating a denial-of-service (DoS) risk.

The Red Hat Product Security team has assessed the severity of this vulnerability as High, given that it can be remotely triggered without authentication or user interaction. Successful exploitation allows an attacker to crash services or applications relying on libsoup for HTTP multipart message processing. The vulnerability’s root cause is a lack of proper bounds checking that results in an integer underflow and subsequent denial-of-service.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, Red Hat recommends avoiding the use of libsoup with untrusted or unauthenticated multipart HTTP message sources until updated packages are available. Administrators can deploy application-level filters or HTTP proxies that reject malformed multipart requests. It is strongly advised to apply vendor-supplied patches as soon as they are released to address this integer underflow vulnerability and restore the stability of affected services.