CVE-2026-0719 is a stack-based buffer overflow vulnerability found in the libsoup HTTP library, which is widely used in GNOME and other Linux applications for network communication. The vulnerability stems from a flaw in the NTLM authentication mechanism within libsoup, where processing extremely long passwords causes an integer overflow in size calculations. Specifically, the use of signed integers leads to an overflow during the calculation of buffer sizes, resulting in insufficient memory allocation on the stack. Subsequently, unsafe memory copying operations occur, which can overwrite adjacent memory regions. This memory corruption can cause the affected applications to crash unexpectedly, leading to denial-of-service (DoS) conditions. The vulnerability is remotely exploitable without requiring any privileges or user interaction, making it particularly dangerous in networked environments. The affected product is Red Hat Enterprise Linux 10, which bundles libsoup and GNOME components. Although no public exploits have been reported yet, the CVSS v3.1 score of 8.6 reflects a high severity due to the ease of exploitation and potential impact on system availability and partial compromise of confidentiality and integrity. The flaw highlights the risks of improper integer handling in security-critical code paths such as authentication.

The primary impact of CVE-2026-0719 is denial of service, as vulnerable applications using libsoup may crash unexpectedly when processing maliciously crafted NTLM authentication requests with extremely long passwords. This can disrupt network services, degrade system availability, and potentially cause cascading failures in dependent applications. Additionally, the underlying memory corruption could be leveraged in future exploit variants to achieve code execution or escalate privileges, although this has not been observed yet. The vulnerability affects confidentiality and integrity to a lesser extent due to the possibility of memory corruption, which might expose sensitive data or allow tampering under certain conditions. Organizations relying on Red Hat Enterprise Linux 10 and GNOME-based network applications are at risk of service outages and potential security breaches. The remote, unauthenticated nature of the exploit increases the threat surface, especially for internet-facing services. The lack of known exploits currently provides a window for proactive mitigation before active attacks emerge.

Organizations should monitor Red Hat and GNOME security advisories closely and apply patches for libsoup and related components as soon as they become available. In the interim, network administrators can implement filtering or rate limiting on NTLM authentication requests to reduce exposure to maliciously crafted inputs. Disabling NTLM authentication where feasible or restricting it to trusted networks can also mitigate risk. Application developers should audit code paths involving signed integer arithmetic in buffer size calculations and adopt safer programming practices such as using unsigned integers and explicit bounds checking. Employing runtime protections like stack canaries, address space layout randomization (ASLR), and memory-safe languages or libraries can reduce exploitation likelihood. Regular vulnerability scanning and penetration testing focused on authentication mechanisms will help detect similar issues early. Finally, maintaining comprehensive logging and monitoring for abnormal application crashes or authentication failures can aid in rapid detection and response.