CVE-2026-0099: Android Local Privilege Escalation via HostEmulationManager Logic Error

Technical summary

CVE-2026-0099 is a privilege escalation vulnerability in the onNullBinding method of HostEmulationManager.java. The flaw allows a local attacker to launch arbitrary activities from the background due to improper validation logic in the binding request handler. The vulnerability is classified under CWE-273 (Improper Privilege Management) and carries a CVSS 3.1 score of 7.8 (HIGH severity). The attack vector is local, requires low complexity, and necessitates user interaction but does not require additional execution privileges beyond a standard app installation context.

Business impact

Successful exploitation enables unauthorized activity launching, allowing attackers to silently execute sensitive functions, exfiltrate data, or trigger privileged operations without user awareness. For enterprises, this could result in unauthorized access to sensitive features, data theft, or lateral movement within device ecosystems. Users managing sensitive data or authentication flows are at elevated risk if a compromised app exploits this vector.

Affected systems

This vulnerability affects Google Android across multiple versions and configurations. The specific affected versions and security patch levels have not been detailed in the available advisories. Organizations should verify their Android version against Google's official security bulletin to determine patch availability and timeline.

Exploitability

This is a local privilege escalation requiring an attacker to already have an installed app on the device—a realistic precondition given the prevalence of app-based attacks. The flaw does not require elevated initial privileges, making it attractive for privilege escalation chains. However, exploitation does require user interaction, which slightly lowers the attack surface but remains achievable through social engineering or automated triggers within the attacker's app context. The vulnerability is not currently tracked in the CISA Known Exploited Vulnerabilities catalog, but local privilege escalations of this nature typically attract security research attention.

Remediation

Apply the security patch when released by Google for your specific Android device and security patch level. Patches address the logic error in the onNullBinding validation. In the interim, avoid installing apps from untrusted sources and monitor app permissions carefully. Organizations should enforce device management policies that limit app installation to curated app stores and enable security event monitoring for suspicious activity launches.

Patch guidance

Contact your device manufacturer or check Google's Android Security & Privacy Year in Review and monthly security bulletins for the specific patch version addressing CVE-2026-0099. Apply patches to all affected devices as soon as they become available. Verify patch application by checking the Security Patch Level in Device Settings > About Phone. For enterprise deployments, coordinate patch rollout through your mobile device management (MDM) solution to ensure comprehensive coverage.

Detection guidance

Monitor system logs for unexpected activity launches originating from background processes or from apps lacking corresponding foreground context. On managed devices, alert on abnormal inter-process communication (IPC) binding requests that bypass standard framework validation. Enterprise SOC teams should review app behavior telemetry for unusual activity launches and cross-reference with known malicious app signatures. Endpoint detection and response (EDR) solutions targeting Android can flag suspicious IPC patterns as early indicators of exploitation attempts.

Why prioritize this

This vulnerability merits prompt attention due to its HIGH CVSS score, local attack vector, and role in privilege escalation chains. Local privilege escalations are foundational techniques in multi-stage attacks and can enable further lateral movement, data theft, or persistent compromise. While the KEV program does not currently track it, the ease of delivery (via installed app) and lack of elevated privilege requirements make it an attractive target for threat actors. Organizations should treat this as a critical patch priority for end-user and corporate-managed devices.

Risk score, explained

The CVSS 3.1 score of 7.8 (HIGH) reflects the combination of local attack vector (AV:L), low attack complexity (AC:L), low privilege requirements (PR:L), and high impact across confidentiality, integrity, and availability (C:H/I:H/A:H). The score does not account for in-the-wild exploitation or threat actor interest, but the fundamental capability to escalate privileges and impact core system functions justifies the HIGH rating. The requirement for user interaction (UI:N in the vector) was assessed as not requiring active, targeted user action beyond normal device use patterns.

Frequently asked questions