CVE-2026-49306 in HarmonyOS
Summary
by MITRE • 08/17/2026
UAF vulnerability in the time and time zone module. Impact: Successful exploitation of this vulnerability may affect availability.
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Analysis
by VulDB Data Team • 08/17/2026
The identified issue represents an Use-After-Free (UAF) vulnerability located within the system's time and time zone management subsystem, a critical component responsible for maintaining accurate temporal data across operating environments. This type of memory corruption error occurs when a program continues to use a pointer after the memory it points to has been freed or reallocated. In the context of time handling modules, this flaw typically arises from improper lifecycle management of objects that store timezone definitions, daylight saving time rules, or cached timestamp structures. When an application or system service releases these resources but retains references to them for subsequent operations such as clock synchronization, log generation, or scheduled task execution, it creates a dangerous state where the program may access stale memory addresses.
From a technical perspective, this vulnerability is classified under CWE-416, which denotes Use After Free conditions that can lead to arbitrary code execution or denial of service depending on how the freed memory is subsequently utilized and what data resides in that location at the time of access. The specific impact noted as affecting availability suggests that exploitation likely results in a crash, segmentation fault, or undefined behavior within the process handling time-sensitive operations rather than immediate remote code execution. This could manifest as application crashes during high-load scenarios where frequent timezone updates occur, such as when processing logs from distributed systems spanning multiple regions or when automated scripts adjust system clocks based on external network sources.
The operational impact of this vulnerability is primarily centered around service disruption and reliability degradation. Systems relying heavily on precise timing for security protocols like Kerberos authentication, TLS certificate validation, or database transaction ordering may experience failures if the underlying time module becomes unstable due to memory corruption. An attacker who can trigger specific sequences of timezone changes or log entries might induce a denial-of-service condition by causing repeated crashes in critical system services. This undermines the integrity and availability pillars of the CIA triad, potentially leading to cascading failures in dependent applications that assume consistent temporal behavior from the operating system core.
Mitigation strategies should focus on both immediate remediation and long-term architectural improvements. The primary solution involves applying vendor-provided patches that correct the memory management logic within the time module, ensuring proper reference counting or smart pointer usage to prevent access after deallocation. In environments where patching is not immediately feasible, administrators can mitigate risk by restricting untrusted input from triggering timezone configuration changes and limiting the privileges of services that interact directly with low-level time APIs. Furthermore, enabling memory protection features such as Address Space Layout Randomization (ASLR) and Heap Protection mechanisms can reduce the exploitability of UAF vulnerabilities by making it harder for attackers to predict memory layouts or control execution flow after a crash occurs.
This vulnerability aligns with MITRE ATT&CK techniques related to resource hijacking and denial of service, specifically those involving local privilege escalation paths that leverage system instability. Security teams should monitor logs for unexpected process terminations in time-related services and implement runtime application self-protection (RASP) solutions where available to detect anomalous memory access patterns indicative of exploitation attempts. Regular auditing of code handling temporal data against CWE-416 guidelines is also recommended to prevent similar defects from being introduced during future development cycles, ensuring robustness in critical infrastructure components that underpin system reliability and security posture.