External risk intelligence

Android Audio Decoder Out of Bounds Write Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-36937

The vulnerability exists in an audio decoder component of the Android operating system. While reachable via network vectors, audio processing libraries are typically internal media-handling components not exposed as internet-facing services, gateways, or public-facing web applications in standard deployment patterns.

Out-of-bounds Write

Google Android

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in Android's audio decoder could allow for remote code execution without user interaction, posing a significant risk. The primary concern is confirming whether this specific component is exposed or relevant to our environment.

Flaw in audio processing allows remote code execution.
Critical risk if exploitable in our systems.
Verify exposure; confirm relevance to our environment.

Attack Path

How an attacker could exploit the issue

An attacker could trigger this vulnerability by sending specially crafted data to a vulnerable audio processing component within Android. This could potentially lead to remote code execution on the affected device.

No entry conditions required.
Triggered by sending crafted audio data.
Risk of remote code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an attacker to execute arbitrary code on a device when processing specially crafted audio data. This could potentially affect the confidentiality, integrity, and availability of the affected system.

Arbitrary code execution.
Processing of malicious audio data.
System compromise and data loss.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the Android audio decoder component likely falls under the purview of the platform or infrastructure teams responsible for the operating system's core functionalities. The immediate priority is to identify all Android devices running the affected component, confirm their exposure and business criticality, and then assign ownership for remediation planning.

Platform or infrastructure teams own.
Verify device exposure and criticality.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Android audio decoder component affected by CVE-2025-36937?

This component is a core part of the Android operating system responsible for interpreting and processing audio data. It functions as a low-level library that enables devices to handle various media formats and streams, essentially acting as the translation layer between raw audio files or network traffic and the sounds you hear on your phone or tablet.

What does an out-of-bounds write mean for this vulnerability?

Classified as CWE-787, this weakness occurs when the decoder fails to properly verify the size of incoming audio data before writing it into memory. Because the code writes beyond the intended storage space, an attacker can overwrite adjacent memory. In the context of CVE-2025-36937, this flaw can be leveraged to execute unauthorized instructions, allowing for potential system-wide control.

How is this vulnerability triggered?

The flaw is triggered when the system processes specially crafted audio data. The attacker does not need to bypass any security gates, gain prior access, or wait for a user to click a link. Simply sending this malicious data to the audio processing component is sufficient to initiate the vulnerability. It is not triggered by standard, well-formed audio files used in everyday media playback.

Is my device at risk based on Halo Surface Signal?

Halo Surface Signal notes that while this bug is technically reachable via network vectors, the audio decoder is an internal media-handling component. It is generally not exposed as an internet-facing service, gateway, or public-facing application. Therefore, it is very unlikely to be directly accessible from the internet in standard Android configurations.

Do I need to take action if I manage Android devices?

Yes, you should prioritize identifying which devices in your environment are running affected versions of the Android operating system. Since this involves a core component of the platform, remediation typically requires applying system-level updates provided by the vendor. Coordinate with your infrastructure teams to confirm device exposure and ensure the latest security patches are scheduled for deployment.

References

source.android.com/security/bulletin/pixel/2025-12-01

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.