CVE-2026-49927: Integer Overflow Privilege Escalation

CVE-2026-49927 Overview

CVE-2026-49927 is an integer overflow vulnerability affecting multiple locations in Android. The flaw enables an out-of-bounds write that can be leveraged for local privilege escalation. Exploitation requires no user interaction and no additional execution privileges beyond a low-privileged local context. The issue is tracked in the Android Security Bulletin for September 2026 and is classified under [CWE-190] Integer Overflow or Wraparound.

Critical Impact
A local attacker with low privileges can trigger an out-of-bounds write via integer overflow, achieving privilege escalation without user interaction and compromising confidentiality, integrity, and availability of the affected device.

Affected Products

Android (multiple components — see the Android Security Bulletin for the definitive list)
Devices receiving the September 2026 Android security patch level
Downstream OEM Android distributions incorporating the vulnerable code paths

Discovery Timeline

2026-09-08 - CVE-2026-49927 published to NVD
2026-09-08 - Last updated in NVD database
2026-09-01 - Referenced in the Android Security Bulletin September 2026

Technical Details for CVE-2026-49927

Vulnerability Analysis

The vulnerability is an integer overflow that occurs in multiple code locations within Android. When affected arithmetic operations wrap around, subsequent length or offset calculations produce values smaller than intended. The code then performs a write operation using the miscalculated size, resulting in an out-of-bounds write beyond the allocated buffer. This memory corruption primitive is sufficient to achieve local escalation of privilege. Because the attack vector is local and no user interaction is required, a malicious application already installed on the device can trigger the flaw automatically.

Root Cause

The underlying weakness is [CWE-190] Integer Overflow or Wraparound. Size or offset computations lack bounds validation, allowing attacker-influenced inputs to overflow integer types. The overflowed value is then trusted by downstream allocation or copy routines, breaking the invariant between allocation size and actual bytes written.

Attack Vector

Exploitation requires local access with low privileges, such as a third-party application executing in a standard sandbox. The attacker submits crafted input that triggers the vulnerable arithmetic path. The resulting out-of-bounds write corrupts adjacent memory structures, enabling privilege escalation to a higher-privileged context. No user interaction is required, and the scope remains unchanged per the CVSS vector.

No public proof-of-concept has been released. Refer to the Android Security Bulletin September 2026 for component-level technical details.

Detection Methods for CVE-2026-49927

Indicators of Compromise

Unexpected native crashes or tombstone files in /data/tombstones/ referencing memory corruption in the affected components.
Applications requesting elevated capabilities or spawning processes outside their normal sandbox scope.
Kernel or system service log entries indicating aborted writes, SIGSEGV, or SIGABRT in privileged processes.

Detection Strategies

Monitor Android devices for applications that trigger repeated native crashes in system services, which may indicate exploitation attempts.
Baseline installed application behavior and flag processes that gain unexpected privileges post-launch.
Correlate mobile telemetry with the September 2026 Android patch level to identify unpatched devices in the fleet.

Monitoring Recommendations

Enforce mobile device management policies that report the current Android security patch level and quarantine devices below the September 2026 baseline.
Ingest mobile threat defense telemetry into a central data lake for anomaly analysis across the device fleet.
Alert on privilege escalation indicators such as new SELinux denials, unexpected uid transitions, or unauthorized changes to protected configuration paths.

How to Mitigate CVE-2026-49927

Immediate Actions Required

Apply the September 2026 Android security patch level (2026-09-01 or later) as soon as it is available for the device.
Inventory all managed Android devices and prioritize patching for high-risk users and privileged accounts.
Restrict installation of applications from unverified sources to reduce the population of potential local attackers.

Patch Information

Google addressed CVE-2026-49927 in the Android Security Bulletin September 2026. Device availability depends on the original equipment manufacturer and carrier. Confirm that affected devices report a security patch level of 2026-09-01 or later after update. OEM downstream patches may be released on independent schedules — track vendor advisories for each supported device model.

Workarounds

Limit device access to trusted application sources such as Google Play with Play Protect enabled.
Remove or disable untrusted third-party applications, particularly those requesting broad permissions.
Enforce mobile device management policies that block sideloading and restrict developer options on production devices.

bash

# Verify the current Android security patch level on a managed device
adb shell getprop ro.build.version.security_patch
# Expected output for patched devices: 2026-09-01 or later