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Fencer Vulns
high 7.8

CVE-2025-6663 json

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

published 2025-07-07 16 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-20240

cvss
7.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

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.

Patch / fix

  • gstreamer gstreamer 1.26.3
  • gst-plugins-bad1.0 Debian 14, Debian 13 1.26.2-3

debian advisories DEBIAN-CVE-2025-6663

  • gst-plugins-bad Alpine 3.24, Alpine 3.23, Alpine 3.22 1.26.3-r0

alpine advisories ALPINE-CVE-2025-6663

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-6663 updated cvss 7.8

gstreamer: GStreamer Code Execution Vulnerability

  • Red Hat Enterprise Linux 6 gstreamer, gstreamer-tools Red Hat Enterprise Linux 7 gstreamer, gstreamer1, gstreamer-tools Red Hat Enterprise Linux 8 gstreamer1, mingw32-gstreamer1, mingw64-gstreamer1 Red Hat Enterprise Linux 9 gstreamer1 Red Hat Enterprise Linux 10 gstreamer1
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
16 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • GStreamer GStreamer

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.