CVE-2026-0135: Android Modem Buffer Read RCE

Technical summary

This vulnerability exploits an out-of-bounds read condition (CWE-125) in the modem subsystem due to missing bounds validation. The absence of proper input sanitization allows a local threat actor to read beyond allocated buffer boundaries, potentially disclosing kernel memory or heap contents that can be leveraged for code execution. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects local vector attack surface, low complexity exploitation, and requirement for low-level user privileges, with high impact across confidentiality, integrity, and availability.

Business impact

A successful exploitation chain could grant attackers persistent control of Android devices within your organization's fleet, leading to data exfiltration, credential theft, SMS interception, or malware persistence. Modem vulnerabilities are particularly concerning because they operate at a system level below standard Android security boundaries. For enterprises managing company-issued devices, this vulnerability poses elevated risk to sensitive communications and authentication mechanisms.

Affected systems

Google Android devices are affected. The vulnerability resides in the modem component, which is present across all Android phone and tablet variants. Exact version ranges and device models should be cross-referenced with Google's official security bulletin and firmware release notes, as those details are not yet fully enumerated in early disclosure.

Exploitability

The vulnerability requires local code execution privileges to trigger; an attacker cannot exploit it remotely over the network. However, once initial local access is obtained—through a separate vulnerability, social engineering, or legitimate user compromise—the lack of user interaction required and the straightforward nature of the bounds check bypass (low complexity) make this a high-value stepping stone for privilege escalation or lateral movement. The modem's privileged execution context amplifies impact significantly.

Remediation

Apply the Android security patch corresponding to the June 2026 security bulletin that addresses this vulnerability. Google typically releases monthly security patches; verify the specific affected build numbers and download the latest OTA update through device settings. For organization-managed devices, coordinate with your mobile device management (MDM) solution to push patches enterprise-wide.

Patch guidance

Check Google's official Android Security & Privacy Year-Round Report for June 2026 and locate the patch level that resolves CVE-2026-0135. Device-level patching is performed via over-the-air updates in Settings > System > System Update. For managed deployments, ensure your MDM configuration enforces patch deployment within 30 days of release. If your devices are on carrier-locked firmware, coordinate with the carrier for timely modem firmware updates, as they may lag vendor releases.

Detection guidance

Monitor system logs for unauthorized modem interactions or memory access violations. Intrusion detection systems should flag attempts to read modem memory or trigger out-of-bounds conditions. Since exploitation typically requires local access, focus detection on lateral movement indicators post-compromise (privilege escalation attempts, kernel module loading, or unusual system-level process spawning). Forensic analysis of compromised devices should examine modem crash dumps and kernel logs for evidence of exploitation.

Why prioritize this

This vulnerability merits urgent prioritization due to its local privilege escalation potential, high CVSS score (7.8), and direct access to the modem's privileged execution context. Although not yet listed in CISA's Known Exploited Vulnerabilities catalog, the combination of low exploitation complexity and high confidentiality/integrity/availability impact makes it attractive to sophisticated threat actors targeting enterprise Android fleets. Devices should be patched within 30 days of patch availability.

Risk score, explained

The CVSS 3.1 score of 7.8 (HIGH) reflects a locally-exploitable flaw requiring low user privilege but delivering complete system compromise potential (high C/I/A impact). The absence of attack complexity and user interaction requirements elevates practical risk. However, the local-only attack vector prevents a critical rating. In enterprise contexts, the rating may escalate if perimeter defenses have been breached or insider threat posture is weak.

Frequently asked questions