CVE-2026-12891: Gstreamer

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

A flaw was found in the GStreamer gst-plugins-bad package. When processing a malformed H.266/VVC video stream with a crafted aspect ratio indicator value, the H.266 parser performs an out-of-bounds read of up to 8 bytes from adjacent memory. This flaw allows an attacker to craft a malicious H.266 video file or stream that, when processed by a GStreamer-based application, could leak limited memory contents through video metadata, potentially exposing sensitive information from the application's address space.

Affected products

• Gstreamer Gstreamer: affected versions not specified
• Red Hat Enterprise Linux: version 8.0 only; version 9.0 only; version 10.0 only

Published 2026-06-23. Last modified 2026-07-01.