CVE-2026-1761 is a stack-based buffer overflow vulnerability identified in libsoup, a widely used HTTP client and server library integrated into Red Hat Enterprise Linux 10. The flaw occurs during the parsing of multipart HTTP responses due to an incorrect length calculation, which leads to a buffer overflow on the stack. This vulnerability can be triggered remotely by an attacker who sends a specially crafted multipart HTTP response to an application that uses libsoup to process HTTP responses. Because the vulnerability does not require any authentication or user interaction, it can be exploited by simply convincing a vulnerable client or server to process a malicious HTTP response. Successful exploitation can cause memory corruption, potentially resulting in application crashes or arbitrary code execution, allowing attackers to execute malicious code with the privileges of the affected application. The vulnerability has a CVSS v3.1 score of 8.6, reflecting its high severity, with an attack vector of network, low attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the nature of the vulnerability and its ease of exploitation make it a significant risk. The vulnerability affects all applications on Red Hat Enterprise Linux 10 that rely on libsoup for HTTP communication, especially those handling untrusted or external HTTP responses, such as web browsers, network services, or middleware components.

For European organizations, this vulnerability poses a substantial risk, particularly for those using Red Hat Enterprise Linux 10 in environments where applications consume HTTP responses from untrusted or external sources. Exploitation could lead to arbitrary code execution, enabling attackers to compromise confidentiality by accessing sensitive data, integrity by altering data or application behavior, and availability by causing application crashes or denial of service. Critical infrastructure sectors, financial institutions, and government agencies that rely on Red Hat Enterprise Linux 10 for network-facing services or internal applications could face operational disruptions or data breaches. The lack of authentication or user interaction requirements lowers the barrier for exploitation, increasing the threat landscape. Additionally, the vulnerability could be leveraged as an initial attack vector for lateral movement within networks. The absence of known exploits in the wild currently reduces immediate risk but does not diminish the urgency for remediation given the high CVSS score and potential impact.

Organizations should prioritize applying official patches or updates from Red Hat as soon as they become available to address this vulnerability. In the interim, network-level controls should be implemented to limit exposure to untrusted HTTP servers, including firewall rules and proxy filtering to restrict or monitor multipart HTTP responses. Application-level mitigations include configuring applications to validate and sanitize HTTP responses rigorously and employing runtime protections such as stack canaries, Address Space Layout Randomization (ASLR), and Data Execution Prevention (DEP) to reduce exploitation success. Security teams should conduct thorough audits of applications using libsoup to identify and isolate vulnerable components. Intrusion detection systems (IDS) and endpoint detection and response (EDR) solutions should be tuned to detect anomalous multipart HTTP traffic patterns. Additionally, organizations should educate developers and system administrators about the risks of processing untrusted HTTP responses and encourage secure coding and deployment practices.