CVE-2026-12891: gstreamer Out-of-bounds Read

Vulnerability summary

CVE-2026-12891 is a medium (CVSS 4.3) Out-of-bounds Read vulnerability in gstreamer. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.5% of scored vulnerabilities.

Timeline

1. 23-06-2026
   PublishedVulnerability first disclosed.
2. 10-09-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.