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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-6663

GStreamer H266 Codec Parsing Stack-based Buffer Overflow Remote Code Execution Vulnerability.

HIGH 7.8EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.0
7.8 HIGHCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
0.39% probability · 33th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-121, CWE-787
Affected
gstreamer/gstreamer
Source
zdi-disclosures@trendmicro.com
EPSS trend
0%3%5%27 October 2026: 0.39%27 October 202627 October 2026

EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.