CVE-2025-4948: Libsoup: integer underflow in soup_multipart_new_from_message() leading to denial of service in libsoup

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-19 · updated 2026-11-01
Weakness: CWE-191

Description

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.

Affected products

Libsoup: through 3.6.5
Red Hat Enterprise Linux 10: all versions — fixed in 0:3.6.5-3.el10_0.6
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:2.62.2-9.el7_9
Red Hat Enterprise Linux 8: all versions — fixed in 0:2.62.3-9.el8_10
Red Hat Enterprise Linux 8.2 Advanced Update Support: all versions — fixed in 0:2.62.3-1.el8_2.5
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:2.62.3-2.el8_4.5
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:2.62.3-2.el8_6.5
Red Hat Enterprise Linux 8.6 Telecommunications Update Service: all versions — fixed in 0:2.62.3-2.el8_6.5
Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions: all versions — fixed in 0:2.62.3-2.el8_6.5
Red Hat Enterprise Linux 8.8 Extended Update Support: all versions — fixed in 0:2.62.3-3.el8_8.5
Red Hat Enterprise Linux 9: all versions — fixed in 0:2.72.0-10.el9_6.2
Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions: all versions — fixed in 0:2.72.0-8.el9_0.5
Red Hat Enterprise Linux 9.2 Extended Update Support: all versions — fixed in 0:2.72.0-8.el9_2.5
Red Hat Enterprise Linux 9.4 Extended Update Support: all versions — fixed in 0:2.72.0-8.el9_4.5

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:3.6.5-3.el10_0.6; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:2.62.2-9.el7_9; Red Hat Enterprise Linux 8 0:2.62.3-9.el8_10; Red Hat Enterprise Linux 8.2 Advanced Update Support 0:2.62.3-1.el8_2.5; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:2.62.3-2.el8_4.5; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.62.3-2.el8_6.5; Red Hat Enterprise Linux 8.6 Telecommunications Update Service 0:2.62.3-2.el8_6.5; Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 0:2.62.3-2.el8_6.5; Red Hat Enterprise Linux 8.8 Extended Update Support 0:2.62.3-3.el8_8.5; Red Hat Enterprise Linux 9 0:2.72.0-10.el9_6.2; Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 0:2.72.0-8.el9_0.5; Red Hat Enterprise Linux 9.2 Extended Update Support 0:2.72.0-8.el9_2.5. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-4948 or the next vulnerability affects your stack