A flaw was found in the GLib Base64 encoding routine when processing very large input data. Because of an integer overflow during length calculation, the library can miscalculate buffer boundaries, causing memory writes outside the allocated buffer. This results in undefined behavior such as crashes or unpredictable execution, which could potentially allow an attacker to corrupt memory or, if sufficient control is obtained, execute arbitrary code. The weakness corresponds to out-of-bounds write (CWE-124 / CWE-787) and integer overflow (CWE-190).

Affected systems are Red Hat Enterprise Linux releases 6 through 10. The vulnerability exists in the GLib package bundled with those operating systems, which is widely used by many applications and system components. No specific product versions are listed beyond the OS families, but any installation of GLib on those RHEL releases is potentially vulnerable.

The CVSS score of 4.2 indicates a low severity impact, and the EPSS score of less than 1 % shows a very low current exploitation probability. The issue has not been listed in the CISA Known Exploited Vulnerabilities catalog. The likely attack vector is feeding large or malformed Base64 input to any application that uses GLib’s g_base64_encode routine. An attacker would need to supply such data, and the vulnerability would manifest as a crash or corruption; no public exploit demonstrates attacker control, so the risk is limited but a memory corruption flaw remains. Until an update is released, systems should consider hardening measures and input validation.