CVE-2026-0719: Libsoup: signed to unsigned conversion error leading to stack-based buffer overflow in libsoup ntlm authentication
A flaw was identified in the NTLM authentication handling of the libsoup HTTP library, used by GNOME and other applications for network communication. When processing extremely long passwords, an internal size calculation can overflow due to improper use of signed integers. This results in incorrect memory allocation on the stack, followed by unsafe memory copying. As a result, applications using libsoup may crash unexpectedly, creating a denial-of-service risk.
Other sources
A stack-based buffer overflow vulnerability exists in the md4sum() function of libsoup’s NTLM authentication module (SoupAuthNTLM). When NTLM authentication is enabled, insufficient bounds checking on stack-allocated buffers can allow a local attacker to overwrite adjacent memory. This may result in arbitrary code execution with the privileges of the affected application. Multiple widely deployed components, including WebKit, Evolution, GVfs, and gnome-online-accounts, enable NTLM by default, increasing exposure.
— Red Hat
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-0719?
CVE-2026-0719 has been classified with a high severity due to its potential to allow local attackers to exploit a buffer overflow.
How can I fix CVE-2026-0719?
To mitigate CVE-2026-0719, it is recommended to update to the latest version of libsoup that addresses the NTLM authentication vulnerability.
Who is affected by CVE-2026-0719?
CVE-2026-0719 primarily affects users of libsoup with NTLM authentication enabled.
What causes CVE-2026-0719?
CVE-2026-0719 is caused by a stack-based buffer overflow vulnerability in the md4sum() function within the NTLM authentication module.
What are the potential consequences of CVE-2026-0719?
Exploitation of CVE-2026-0719 could allow an attacker to overwrite adjacent memory, potentially leading to code execution or system compromise.