CVE-2025-13601 is a heap-based buffer overflow vulnerability identified in the glib library, specifically within the g_escape_uri_string() function. This function is responsible for escaping URI strings by replacing unacceptable characters with percent-encoded equivalents. The vulnerability stems from an integer overflow or wraparound during the calculation of the buffer size needed to store the escaped string. When the input string contains a very large number of characters that require escaping, the calculation of the escaped string's length can overflow the integer variable used for size determination. This overflow results in allocating a buffer smaller than necessary. Subsequently, when the function writes the escaped characters into this undersized buffer, it causes a heap-based buffer overflow by writing beyond the allocated memory boundary. This memory corruption can lead to unpredictable behavior, including potential arbitrary code execution or denial of service. The vulnerability does not require any privileges or user interaction to exploit, but it requires local access since the attack vector is local (AV:L). The CVSS 3.1 base score is 7.7, reflecting high severity due to the impact on integrity and availability. The affected product is Red Hat Enterprise Linux 10, which includes the vulnerable glib version. No public exploits are currently known, but the flaw's nature makes it a significant risk once weaponized. The issue was published on November 26, 2025, and is assigned CVE-2025-13601. The vulnerability is critical for applications relying on glib for URI escaping, especially those processing untrusted input strings with many escapable characters.

For European organizations, this vulnerability poses a significant risk to systems running Red Hat Enterprise Linux 10 or other distributions incorporating the vulnerable glib version. Exploitation could lead to arbitrary code execution or denial of service, impacting the integrity and availability of critical services. This is particularly concerning for sectors such as finance, telecommunications, government, and critical infrastructure, where Linux-based servers are prevalent. The local attack vector limits remote exploitation but does not eliminate risk in environments where multiple users have local access or where attackers can execute code locally via other vulnerabilities or social engineering. The absence of required privileges or user interaction increases the threat level in multi-tenant or shared environments. Disruption or compromise of key systems could lead to data loss, service outages, or lateral movement within networks. Given the widespread use of Red Hat Enterprise Linux in European enterprises and public sector organizations, the vulnerability could have broad operational and security impacts if left unmitigated.

1. Apply official patches or updates from Red Hat as soon as they become available to address the vulnerability in glib. 2. In the interim, audit applications and services that utilize the g_escape_uri_string() function to identify potential exposure, especially those processing untrusted or user-supplied input. 3. Employ runtime memory protection mechanisms such as Address Space Layout Randomization (ASLR), stack canaries, and heap protections to mitigate exploitation risk. 4. Use static and dynamic analysis tools to detect unsafe usage patterns of URI escaping functions in custom or third-party code. 5. Restrict local access to critical systems to trusted users only, minimizing the risk of local exploitation. 6. Monitor system logs and behavior for signs of memory corruption or anomalous crashes that could indicate exploitation attempts. 7. Consider deploying intrusion detection systems capable of identifying heap overflow exploitation techniques. 8. Educate system administrators and developers about the vulnerability and encourage secure coding practices to avoid similar issues.