GStreamer H266 Codec Parser stack-based overflow

Summaryinfo

A vulnerability, which was classified as critical, has been found in GStreamer. This affects an unknown part of the component H266 Codec Parser. This manipulation causes stack-based overflow. This vulnerability appears as CVE-2025-6663. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability has been found in GStreamer (affected version unknown) and classified as critical. Affected by this vulnerability is an unknown functionality of the component H266 Codec Parser. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at zerodayinitiative.com. This vulnerability is known as CVE-2025-6663 since 06/25/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/14/2025).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-20240). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Multimedia Processing Software

Name

• GStreamer

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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