CVE-2025-6663 GStreamer H266 Codec Parsing Stack-based Buffer Overflow Remote Code Execution Vulnerability

High 7.8 Published 7 Jul 2025 Updated 7 Jul 2025

Remote attackers can execute arbitrary code via a stack-based buffer overflow in GStreamer's H266 codec parsing.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2025-6663?

CVE-2025-6663 is a high-severity memory corruption vulnerability in Gstreamer Gstreamer, published on 7 Jul 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

GStreamer H266 Codec Parsing Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GStreamer. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the parsing of H266 sei messages. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-27381.

Weakness: CWE-787, CWE-121

Which versions are affected by CVE-2025-6663?

It affects 1 product.

Products include Gstreamer Gstreamer.

How do I fix CVE-2025-6663?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-6663 being exploited?

There is no known exploitation of CVE-2025-6663 in the wild and no public exploit code.

All Gstreamer Gstreamer vulnerabilities

Sources

Also known as DEBIAN-CVE-2025-6663, GHSA-8539-chjx-chcc, UBUNTU-CVE-2025-6663.