CVE-2026-55301 Overview
CVE-2026-55301 is an out-of-bounds write vulnerability in the Wave6VpuDecFlush function of wave6.c, a component of the Wave6 video decoder driver used in Android devices. The flaw stems from a missing bounds check that allows a local attacker to write beyond the intended buffer boundary. Successful exploitation leads to local privilege escalation without requiring additional execution privileges or user interaction. The vulnerability is tracked under [CWE-120] (Buffer Copy without Checking Size of Input) and was addressed in the Android Security Bulletin September 2026.
Critical Impact
A local attacker can achieve kernel-level privilege escalation on affected Android devices without user interaction, gaining full control over the compromised device.
Affected Products
- Android devices using the Wave6 VPU decoder driver
- Google Pixel devices covered by the September 2026 security bulletin
- Kernel builds incorporating the vulnerable wave6.c driver
Discovery Timeline
- 2026-09-15 - CVE-2026-55301 published to NVD
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-55301
Vulnerability Analysis
The vulnerability resides in the Wave6VpuDecFlush function within wave6.c, the driver source for the Wave6 Video Processing Unit (VPU) decoder. The function performs a write operation on a buffer without validating that the target index or size remains within allocated memory. When triggered, this out-of-bounds write corrupts adjacent kernel memory structures.
Because the vulnerable code executes in kernel context, memory corruption can be leveraged to overwrite security-relevant structures such as function pointers, credential structures, or page tables. An attacker with local access to the device can craft input that reaches the flush handler and manipulate memory beyond the intended write boundary. The result is arbitrary kernel memory corruption suitable for privilege escalation from an unprivileged process to kernel-level execution.
Root Cause
The root cause is a missing bounds check inside Wave6VpuDecFlush before performing a write operation. The function trusts input parameters or internal indices without verifying they fall within the allocated buffer range. This classic [CWE-120] pattern occurs when driver code assumes upstream validation that does not exist, allowing attacker-controlled values to drive out-of-bounds memory writes.
Attack Vector
Exploitation requires local access on the affected Android device. An unprivileged local application interacts with the Wave6 VPU decoder interface, typically through IOCTL calls or device file operations that route into the vulnerable flush routine. No user interaction and no additional execution privileges are required. Because the driver executes in kernel space, successful exploitation grants privileges well beyond those normally available to a sandboxed Android application.
No public proof-of-concept exploit is currently available for CVE-2026-55301. Technical remediation details are documented in the Android Security Bulletin September 2026.
Detection Methods for CVE-2026-55301
Indicators of Compromise
- Unexpected kernel panics or crashes referencing the wave6 driver or Wave6VpuDecFlush in device logs
- Unprivileged applications opening or issuing IOCTLs against Wave6 VPU decoder device nodes outside of legitimate media playback contexts
- Anomalous privilege transitions where a sandboxed application process suddenly executes with elevated UID or SELinux context
Detection Strategies
- Monitor dmesg and kernel ring buffer output for stack traces referencing wave6.c or memory corruption warnings from KASAN-enabled builds
- Audit installed applications for unexpected access to /dev/video* or Wave6 decoder device nodes
- Track SELinux denials related to the media codec domain that may indicate exploitation attempts
Monitoring Recommendations
- Enable Android verified boot and integrity attestation to detect post-exploitation persistence attempts
- Deploy mobile threat defense tooling capable of identifying kernel exploitation behaviors on managed devices
- Correlate device crash telemetry with application install events to surface potentially malicious media applications
How to Mitigate CVE-2026-55301
Immediate Actions Required
- Apply the September 2026 Android security patch level (2026-09-01 or later) to all affected devices
- Prioritize patching for devices with the Wave6 VPU decoder present in the kernel build
- Restrict installation of untrusted applications from sources outside Google Play until devices are updated
Patch Information
Google addressed CVE-2026-55301 in the Android Security Bulletin September 2026. Device manufacturers must integrate the corresponding kernel patch that adds bounds validation to Wave6VpuDecFlush in wave6.c and ship an over-the-air update to end users. Verify the device reports a security patch level of 2026-09-01 or later after updating.
Workarounds
- No official workaround eliminates the vulnerability without applying the vendor patch
- Enforce mobile device management policies that block sideloading and restrict application sources to trusted stores
- Disable or remove applications that require direct access to hardware video decoding interfaces if patching is delayed
# Verify Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch
# Expected output for remediated devices: 2026-09-01 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
