CVE-2026-100231: gst-plugins-bad1.0 Out-of-bounds Write

Vulnerability summary

CVE-2026-100231 is a medium (CVSS 6.1) Out-of-bounds Write vulnerability in gst-plugins-bad1.0. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.8% of scored vulnerabilities.

Timeline

1. 14-10-2026
   PublishedVulnerability first disclosed.
2. 15-10-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in the GStreamer multimedia framework's ASF muxer plugin (asfmux). When writing string metadata tags containing Unicode characters outside the Basic Multilingual Plane (such as emoji) to an ASF container, the plugin incorrectly calculates the buffer size needed for the UTF-16LE representation. The size calculation assumes each Unicode code point requires 2 bytes, but non-BMP characters require 4 bytes (surrogate pairs). This leads to a heap out-of-bounds write when the actual UTF-16LE conversion is written into the undersized buffer. An attacker could exploit this by providing media with crafted metadata tags to an application that transcodes or remuxes to ASF format while preserving metadata, potentially causing a denial of service or limited memory corruption.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.