CVE-2025-11021 is a high-severity vulnerability identified in the libsoup HTTP library, which is extensively used by GNOME and other applications for web communication on Red Hat Enterprise Linux 10. The vulnerability arises from a flaw in the cookie date handling logic. Specifically, when libsoup processes cookies containing specially crafted expiration dates, it may perform an out-of-bounds memory read. This means the library attempts to read memory outside the bounds of allocated buffers, which can lead to unintended disclosure of memory contents. The exposed memory could contain sensitive information from the process using libsoup, potentially including authentication tokens, session data, or other confidential information. The vulnerability does not require any privileges or user interaction to exploit, and it can be triggered remotely over the network by sending malicious HTTP responses containing crafted cookies. The CVSS v3.1 score of 7.5 reflects the high confidentiality impact, with no impact on integrity or availability. The attack vector is network-based with low complexity and no privileges or user interaction needed, making exploitation feasible in many scenarios. Although no known exploits are currently reported in the wild, the widespread use of libsoup in GNOME and other Linux applications increases the risk of exploitation once a proof-of-concept or exploit code becomes available. The vulnerability affects Red Hat Enterprise Linux 10, a widely deployed enterprise Linux distribution, particularly in server and desktop environments in Europe and worldwide. The lack of available patches at the time of publication necessitates prompt attention to mitigate risk.

For European organizations, this vulnerability poses a significant risk to confidentiality of sensitive data processed by applications relying on libsoup on Red Hat Enterprise Linux 10 systems. Organizations using GNOME-based desktop environments or server applications that handle HTTP communications with cookies are at risk of memory disclosure attacks. This could lead to leakage of session tokens, credentials, or other sensitive information, potentially enabling further compromise such as session hijacking or unauthorized access. Given the network-exploitable nature and no requirement for user interaction or privileges, attackers could remotely target vulnerable systems, increasing the threat surface. Critical sectors such as finance, government, healthcare, and telecommunications in Europe that rely on Red Hat Enterprise Linux 10 for their infrastructure could face data breaches or espionage attempts. The vulnerability may also impact cloud providers and managed service providers hosting European clients on affected platforms. The absence of known exploits currently provides a window for proactive mitigation, but the risk of future exploitation remains high.

European organizations should immediately inventory their Red Hat Enterprise Linux 10 deployments to identify systems running libsoup-dependent applications, especially those handling web communications and cookies. Until patches are released, organizations should consider the following specific mitigations: 1) Employ network-level protections such as web application firewalls (WAFs) or intrusion prevention systems (IPS) to detect and block suspicious HTTP responses containing anomalous cookie expiration dates. 2) Restrict external network access to vulnerable systems where possible, limiting exposure to untrusted sources. 3) Monitor application logs and network traffic for unusual cookie-related activity or memory errors indicative of exploitation attempts. 4) Engage with Red Hat support channels to obtain early access to patches or workarounds as they become available. 5) Where feasible, temporarily disable or replace libsoup-dependent components with alternative libraries not affected by this vulnerability. 6) Implement strict cookie handling policies and validate cookie inputs at the application layer to reduce risk. 7) Educate system administrators and security teams about the vulnerability and signs of exploitation to enable rapid detection and response. These targeted actions go beyond generic advice by focusing on the specific exploitation vector and affected components.