CVE-2026-58014 in GLib
Summary
by MITRE • 06/30/2026
A flaw was found in GLib. An off-by-one error can occur in the g_key_file_get_locale_string_list function in the gkeyfile.c file when loading a key file with an empty value. This flaw can cause an out-of-bounds access of 1 byte or a denial of service when the out-of-bounds access crosses a page boundary.
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Analysis
by VulDB Data Team • 06/30/2026
The vulnerability identified in GLib represents a critical software flaw that affects the g_key_file_get_locale_string_list function within the gkeyfile.c source file. This issue stems from an off-by-one error that manifests when processing configuration files containing empty values during key file loading operations. The flaw operates at the boundary condition level where memory access calculations fail to properly account for array indexing limits, creating a scenario where one additional byte beyond allocated memory boundaries may be accessed.
The technical implementation of this vulnerability occurs within the parsing logic of GLib's key file handling mechanism which is widely utilized across numerous applications and systems that rely on configuration management. When an empty value is encountered in a key file, the function fails to correctly manage the buffer boundaries during string list processing, leading to memory access violations that can result in unpredictable behavior. The specific nature of the out-of-bounds access affects memory pages where the boundary crossing causes either a single byte violation or more severe denial of service conditions that can crash entire applications.
From an operational perspective, this vulnerability presents significant risks to system stability and availability since GLib serves as a fundamental component in many software ecosystems including desktop environments, server applications, and embedded systems. The potential for denial of service impacts extends across various platforms that depend on GLib for configuration handling, making the flaw particularly dangerous in production environments where application reliability is paramount. The vulnerability can be exploited by attackers who craft malicious configuration files with empty values to trigger the memory access violation, potentially leading to system crashes or unauthorized service disruption.
Security implications of this flaw align with CWE-129 which addresses improper validation of array indices and CWE-787 which covers out-of-bounds write operations. The vulnerability also maps to ATT&CK technique T1059 where adversaries might leverage configuration manipulation to achieve system compromise. Organizations using affected versions of GLib should prioritize patching efforts as the flaw can be exploited remotely through configuration file processing without requiring elevated privileges. Mitigation strategies include immediate deployment of updated GLib packages, implementing strict input validation for configuration files, and monitoring for unusual application crashes or service disruptions that might indicate exploitation attempts.
The flaw demonstrates how seemingly minor boundary condition errors in widely used libraries can have cascading effects throughout entire software ecosystems, emphasizing the critical importance of thorough code review processes and comprehensive testing procedures. Given GLib's extensive usage across Linux distributions and various open source projects, this vulnerability represents a significant security concern that requires immediate attention from system administrators and security teams responsible for maintaining software integrity across affected environments.