CVE-2026-49878: Google Android RCE Vulnerability

CVE-2026-49878 Overview

CVE-2026-49878 is an out-of-bounds write vulnerability in the wpas_handle_robust_av_scs_recv_action function within robust_av.c, a component of the Android wpa_supplicant Wi-Fi management stack. A logic error in the code permits memory writes outside allocated bounds when processing incoming Stream Classification Service (SCS) action frames. Successful exploitation leads to remote code execution with System privileges. No user interaction is required to trigger the flaw. Google disclosed the issue in the October 2026 Android Security Bulletin, affecting multiple actively supported Android versions.

Critical Impact
Remote code execution at System privilege level without user interaction, enabling full compromise of the Wi-Fi stack and privileged Android processes.

Affected Products

Google Android 14
Google Android 15
Google Android 16 (including QPR2)
Google Android 17

Discovery Timeline

2026-10-05 - CVE-2026-49878 published to the National Vulnerability Database
2026-10-01 - Google publishes fix in the Android Security Bulletin
2026-10-07 - Last updated in NVD database

Technical Details for CVE-2026-49878

Vulnerability Analysis

The flaw resides in wpas_handle_robust_av_scs_recv_action, the handler for Robust Audio/Video Stream Classification Service action frames in wpa_supplicant. A logic error during parsing of the received action frame produces an out-of-bounds write condition [CWE-787]. Because wpa_supplicant runs with System execution privileges on Android, memory corruption inside this process can be leveraged to achieve code execution within that trust boundary.

The advisory classifies the attack vector as network-based with no user interaction required. However, the attacker needs high privileges relative to the Wi-Fi association context, meaning the exploit path typically involves a crafted action frame delivered over an existing or attacker-influenced Wi-Fi connection.

Root Cause

The root cause is a logic error in the SCS action-frame processing path that fails to correctly validate or bound the data written to a target buffer. When the handler processes attacker-controlled fields from a Robust AV SCS frame, the write operation exceeds the destination buffer boundary, corrupting adjacent memory inside the wpa_supplicant process.

Attack Vector

An attacker within radio range of the target device, or capable of injecting frames into an associated Wi-Fi link, sends a malformed Robust AV SCS action frame. The wpa_supplicant daemon processes the frame via wpas_handle_robust_av_scs_recv_action, triggering the out-of-bounds write. Successful memory corruption can yield code execution in the System context, bypassing user-level sandbox restrictions.

No verified public exploit or proof-of-concept code is available at publication time. For technical specifics, refer to the Android Security Bulletin October 2026.

Detection Methods for CVE-2026-49878

Indicators of Compromise

Unexpected crashes or restarts of the wpa_supplicant process recorded in logcat or tombstone logs.
Anomalous Wi-Fi disconnections correlated with the receipt of 802.11 action frames from unknown BSSIDs.
Presence of unusual child processes or memory regions spawned by wpa_supplicant.

Detection Strategies

Monitor Android tombstone and dropbox crash artifacts for SIGSEGV or SIGABRT events in wpa_supplicant.
Inspect wireless packet captures for malformed Robust AV SCS action frames (category 19) with abnormal field lengths.
Correlate device integrity attestation failures with Wi-Fi session anomalies in managed fleets.

Monitoring Recommendations

Centralize Android device telemetry, including crash dumps and Wi-Fi events, into a SIEM for anomaly analysis.
Alert on repeated wpa_supplicant restarts across managed devices, which may indicate exploitation attempts.
Track Android security patch level (SPL) across the fleet to identify devices still exposed to the October 2026 bulletin fixes.

How to Mitigate CVE-2026-49878

Immediate Actions Required

Apply the October 2026 Android security patch level (2026-10-01 or later) to all managed Android 14, 15, 16, and 17 devices.
Prioritize patching for devices that frequently connect to untrusted or public Wi-Fi networks.
Enforce patch compliance through Mobile Device Management (MDM) and conditional access policies.

Patch Information

Google addressed CVE-2026-49878 in the Android Security Bulletin October 2026. Devices reporting a security patch level of 2026-10-01 or later include the corrected wpas_handle_robust_av_scs_recv_action logic in robust_av.c. OEM delivery timelines vary; verify builds directly with device manufacturers.

Workarounds

Restrict device connectivity to trusted enterprise Wi-Fi networks until patches are deployed.
Disable Wi-Fi on high-risk devices in untrusted environments where feasible.
Use MDM policies to block connections to open or unknown SSIDs that could be used to deliver crafted action frames.

bash

# Verify Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch
# Expected output for remediated devices: 2026-10-01 or later