CVE-2026-58691 in Android
Summary
by MITRE • 09/15/2026
In FsmReleaseKey of fsm.c, there is a possible permission bypass due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified within the FsmReleaseKey function in fsm.c represents a critical security flaw rooted in insufficient validation of user-supplied or system-generated inputs prior to their processing by kernel-level access control mechanisms. This specific implementation error allows an attacker to bypass intended permission checks, effectively undermining the integrity of the operating system's privilege management architecture. The core technical issue lies in the failure to rigorously verify that the entity requesting the release of a key possesses the necessary authorization levels or adheres to expected state constraints before granting access. By neglecting these critical input validation steps, the function permits operations that should be restricted to higher-privileged contexts, thereby creating an avenue for unauthorized privilege escalation.
From a technical perspective, this flaw aligns with CWE-284, which describes Improper Access Control, and more specifically relates to scenarios where access control decisions are not properly enforced due to logic errors or missing checks in the code path. The absence of proper validation means that the system fails to distinguish between legitimate administrative actions and malicious attempts to manipulate kernel resources. This is particularly dangerous because it occurs within a component likely responsible for managing security tokens, session keys, or file system metadata locks, where trust boundaries are strictly defined but not adequately enforced in this specific code path. The lack of input sanitization allows an attacker to craft requests that appear valid syntactically but violate semantic security policies, leading the kernel to execute actions with elevated privileges without requiring further authentication or authorization checks.
The operational impact of this vulnerability is severe, as it facilitates local escalation of privilege from a lower-privileged user account to higher levels such as SYSTEM or root. This means that any authenticated user on the system can potentially exploit this flaw to gain unrestricted access to sensitive data, modify critical system configurations, install persistent malware, or disable security monitoring tools. The severity is compounded by the fact that no additional execution privileges are required for exploitation; standard user-level code suffices to trigger the vulnerability. Furthermore, because user interaction is not needed, an attacker can automate the exploit process using scripts or background processes without needing to deceive a human operator into performing specific actions like clicking links or opening files. This characteristic makes the vulnerability highly suitable for automated attacks and rapid propagation within compromised environments where initial access has been established through other means such as phishing or web application exploits.
In terms of threat modeling, this vulnerability maps directly to MITRE ATT&CK techniques related to Privilege Escalation via Local Exploitation. Attackers would likely leverage this flaw after gaining a foothold on the target system to elevate their access rights and establish persistence. The ability to escalate privileges without user interaction significantly lowers the barrier for entry for less sophisticated threat actors, increasing the overall risk landscape. Defenders must recognize that such kernel-level flaws can serve as critical pivots in an attack chain, allowing adversaries to move from initial compromise to full system control with minimal effort.
Mitigation strategies should focus on immediate patching of the affected software component by applying vendor-provided updates that address the input validation logic within FsmReleaseKey. Until patches are available, administrators can implement compensating controls such as strict application whitelisting and process monitoring to detect anomalous behavior indicative of privilege escalation attempts. Additionally, enforcing least-privilege principles across all user accounts reduces the attack surface by limiting the potential impact if an exploit is successful. Regular security audits focusing on input validation practices in kernel modules are essential to prevent similar vulnerabilities from being introduced during future development cycles.