CVE-2026-56967 Overview
CVE-2026-56967 is a heap buffer overflow vulnerability in a Cellular Modem component that permits an out-of-bounds write in heap memory. An attacker within radio range can trigger remote code execution over the adjacent network without user interaction and without additional execution privileges. The flaw is tracked in the Android Security Bulletin September 2026 and is classified under [CWE-122] Heap-based Buffer Overflow.
Critical Impact
Attackers within radio proximity can execute arbitrary code on the modem baseband, bypassing user interaction requirements and potentially compromising the cellular processing subsystem.
Affected Products
- Cellular Modem component referenced in the September 2026 Android/Pixel Security Bulletin
- Devices integrating the affected baseband firmware
- See the vendor advisory for the definitive list of affected models and firmware builds
Discovery Timeline
- 2026-09-15 - CVE-2026-56967 published to NVD
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-56967
Vulnerability Analysis
The vulnerability resides in the Cellular Modem firmware and manifests as an out-of-bounds write on the heap. Improper bounds checking during message parsing allows attacker-controlled data to overflow an allocated heap buffer. Because the modem processes untrusted radio-layer input, exploitation does not require any application-level privileges on the host operating system.
Successful exploitation grants code execution in the modem processing context. Baseband compromise can lead to interception of cellular traffic, persistence outside the reach of endpoint controls, and pivoting into the application processor. The absence of a user interaction requirement raises the practical risk for devices operating in public or shared radio environments.
Root Cause
The defect stems from a missing or insufficient length validation when copying data into a heap-allocated buffer. When a crafted radio protocol message specifies a size that exceeds the destination allocation, the copy operation writes past the buffer boundary. This corrupts adjacent heap metadata or function pointers, giving the attacker control over execution flow.
Attack Vector
The vulnerability is reachable over an adjacent network, meaning the attacker must operate a rogue base station or transmitter within radio range of the target device. The attacker sends a malformed cellular protocol message that triggers the heap overflow during parsing. No user interaction, no application installation, and no elevated privileges are required. Technical details are described in the Android Security Bulletin September 2026.
Stop Remote Code Execution Before It Runs
Singularity™ Endpoint detects and blocks exploit attempts at machine speed, including zero-days and novel attack techniques.
Stop Exploit AttemptsDetection Methods for CVE-2026-56967
Indicators of Compromise
- Unexpected modem reboots, radio stack crashes, or baseband firmware faults recorded in device logs
- Presence of unauthorized or unregistered base stations broadcasting in the vicinity of affected devices
- Anomalous cellular signaling patterns or connections to unknown carrier network identifiers
Detection Strategies
- Monitor mobile device management (MDM) telemetry for repeated baseband exceptions or modem service restarts
- Correlate device location data with known IMSI catcher or rogue eNodeB detection feeds
- Track patch compliance status across managed device fleets to identify vulnerable endpoints
Monitoring Recommendations
- Ingest MDM and mobile threat defense logs into the security operations platform for centralized review
- Alert on cellular attach events to unrecognized public land mobile network identifiers
- Review Android bulletin patch level attributes reported by enrolled devices at regular intervals
How to Mitigate CVE-2026-56967
Immediate Actions Required
- Apply the September 2026 Android Security Bulletin patch level to all affected devices as soon as vendor updates are available
- Inventory managed mobile devices and prioritize patching for those operating in high-risk radio environments
- Advise high-risk users to disable cellular radios or use airplane mode in untrusted locations until patched
Patch Information
The fix is delivered through device vendor firmware updates aligned to the September 2026 Android Security Bulletin. Refer to the Android Security Bulletin September 2026 for the security patch level string and per-device availability. Confirm the security patch level on each device after the update completes.
Workarounds
- Disable cellular connectivity and rely on trusted Wi-Fi where operationally feasible until firmware updates are applied
- Enforce MDM policies that require the September 2026 patch level for access to sensitive corporate resources
- Restrict high-value device usage in environments where rogue base station activity cannot be ruled out
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
