CVE-2026-0139: Google Android Modem RCE Vulnerability

CVE-2026-0139 Overview

CVE-2026-0139 is an out-of-bounds write vulnerability in the Android Modem component. The flaw stems from a missing bounds check that allows attackers to write beyond allocated memory buffers. Successful exploitation leads to remote code execution without requiring additional execution privileges or user interaction. Google tracks this issue under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer). The vulnerability affects the Android operating system and was disclosed in the Android Security Bulletin June 2026.

Critical Impact
Remote attackers can execute arbitrary code on affected Android devices through the modem subsystem without user interaction.

Affected Products

Google Android (Pixel devices, see vendor bulletin)
Devices using the affected modem firmware component
Systems referenced in the June 2026 Android Security Bulletin

Discovery Timeline

2026-06-16 - CVE-2026-0139 published to the National Vulnerability Database
2026-06-01 - Google released the Android Security Bulletin addressing the issue
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-0139

Vulnerability Analysis

The vulnerability resides in the Android Modem component, which processes baseband communications between the device and cellular network. A missing bounds check during input handling permits an attacker to write data outside the intended memory region. This memory corruption primitive can be leveraged to overwrite adjacent structures, function pointers, or return addresses. Because the modem operates with elevated privileges relative to user-space applications, exploitation yields remote code execution in a sensitive context. The flaw is classified as [CWE-119], covering improper restriction of memory buffer operations. Exploitation does not require user interaction, making this attractive for opportunistic, network-borne attacks against cellular-connected devices.

Root Cause

The root cause is a missing length validation in the Modem code path that handles attacker-controlled input. Without verifying that the input size fits the destination buffer, the affected routine copies data past the buffer boundary. The condition matches the classic pattern described in [CWE-119], where bounds enforcement is absent or insufficient.

Attack Vector

The attack vector is network-based. An adversary positioned on the cellular network, or operating a rogue base station, can transmit crafted protocol messages to the target device. Because authentication and user interaction are not required for the exploit path itself, the attacker only needs reachability to the modem interface. EPSS data published on 2026-06-18 reports a low near-term exploitation probability, but the technical impact remains high.

No public proof-of-concept code is available. Refer to the Android Security Bulletin June 2026 for the vendor's technical description.

Detection Methods for CVE-2026-0139

Indicators of Compromise

Unexpected modem crashes, resets, or kernel logs referencing baseband faults
Devices repeatedly attaching to unknown or low-signal cellular cells
Anomalous radio interface layer (RIL) messages or unexplained modem firmware state changes

Detection Strategies

Monitor Android logcat and modem ramdump artifacts for repeated baseband exceptions tied to memory faults
Correlate device telemetry to identify clusters of devices crashing in proximity to a single cell tower, which can indicate rogue base station activity
Track Android patch level (ro.build.version.security_patch) across the fleet to identify devices missing the June 2026 update

Monitoring Recommendations

Ingest mobile device management (MDM) compliance data into your SIEM to flag unpatched Android devices
Alert on devices that fail to apply the June 2026 security patch within your defined remediation window
Review enterprise mobility logs for anomalous cellular network behavior associated with managed devices

How to Mitigate CVE-2026-0139

Immediate Actions Required

Apply the June 2026 Android security patch level or later to all affected devices
Inventory devices through MDM to confirm patch deployment status and surface non-compliant endpoints
Prioritize patching for high-risk roles such as executives, engineering, and personnel who travel internationally

Patch Information

Google released a fix in the June 2026 Android Security Bulletin. Devices must report a security patch level of 2026-06-01 or later to be considered remediated. Pixel and partner OEM updates are tracked in the Android Security Bulletin June 2026. Confirm OEM-specific availability with the device manufacturer.

Workarounds

Disable cellular radios on devices that cannot be patched, relying on Wi-Fi only where feasible
Restrict use of unmanaged or end-of-life devices that no longer receive Android security updates
Enforce MDM policies that block enrollment of devices below the required security patch level

bash

# Verify the Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch
# Expected output: 2026-06-01 or later