CVE-2026-56978: gc.c Privilege Escalation Vulnerability

CVE-2026-56978 Overview

CVE-2026-56978 is an out-of-bounds read vulnerability in the get_global_config_item_addr function of gc.c, an Android platform component. The flaw stems from a missing bounds check when accessing global configuration items. A local attacker can exploit the condition to achieve privilege escalation without user interaction and without needing additional execution privileges. The issue is tracked in the Android Security Bulletin for September 2026.

Critical Impact
Local privilege escalation with high impact to confidentiality, integrity, and availability, requiring no user interaction and no prior privileges on the affected device.

Affected Products

Android platform (component containing gc.c)
Devices covered by the Android Security Bulletin September 2026
Google Pixel devices per the Pixel Security Bulletin September 2026

Discovery Timeline

2026-09-15 - CVE-2026-56978 published to the National Vulnerability Database (NVD)
2026-09-17 - Last updated in NVD database
2026-09-01 - Addressed in the Android Security Bulletin September 2026

Technical Details for CVE-2026-56978

Vulnerability Analysis

The vulnerability resides in get_global_config_item_addr, a routine in gc.c that returns the address of a global configuration item. The function fails to validate an index or offset against the bounds of the underlying configuration structure. As a result, it reads memory outside the intended buffer. The read primitive returns an address or data that a local process can use to influence subsequent operations in a privileged context. This is classified under [CWE-120] (Buffer Copy without Checking Size of Input) and manifests as an out-of-bounds read.

Root Cause

The root cause is a missing bounds check on input used to index into the global configuration table. Without validation, the function accesses memory beyond the allocated region. The exposed data can leak sensitive kernel or system state and, in combination with subsequent operations, enables privilege escalation.

Attack Vector

Exploitation requires local access to the device. An unprivileged application or process on the affected Android system can trigger the vulnerable code path by supplying a crafted configuration identifier. No user interaction is required. Successful exploitation elevates privileges within the affected process context.

No public proof-of-concept exploit code is available. Refer to the Android Security Bulletin September 2026 for technical details from the vendor.

Detection Methods for CVE-2026-56978

Indicators of Compromise

Unexpected privilege changes or SELinux denials associated with processes invoking configuration lookup routines.
Anomalous crashes, SIGSEGV, or kernel logs referencing gc.c or get_global_config_item_addr.
Installation of unknown APKs or sideloaded applications on managed devices prior to abnormal system behavior.

Detection Strategies

Monitor Android build fingerprints and security patch levels for devices lacking the September 2026 patch.
Inspect logcat and kernel ring buffers for out-of-bounds access indicators or repeated fault addresses in the affected component.
Correlate application installation events with subsequent privilege escalation or system service anomalies.

Monitoring Recommendations

Deploy mobile threat defense tooling to track patch-level compliance across managed Android fleets.
Alert on devices reporting a security patch level earlier than 2026-09-01 through enterprise mobility management (EMM) or mobile device management (MDM).
Centralize mobile telemetry and correlate with application reputation and behavior data.

How to Mitigate CVE-2026-56978

Immediate Actions Required

Apply the Android security patch level 2026-09-01 or later to all affected devices.
Update Google Pixel devices to the September 2026 Pixel update as published by Google.
Restrict installation of untrusted applications and enforce Google Play Protect on managed endpoints.
Audit enterprise device inventory to identify devices running unpatched Android builds.

Patch Information

Google published the fix in the Android Security Bulletin September 2026. Original Equipment Manufacturers (OEMs) integrate the fix into their vendor-specific security patch level. Devices reporting a security patch level of 2026-09-01 or later contain the fix.

Workarounds

No official vendor workaround is documented; patching is the required remediation.
Limit exposure by prohibiting sideloaded applications and enforcing an allowlist of vetted apps on managed devices.
Decommission or isolate devices that cannot receive the September 2026 patch level.