CVE-2026-73433: Gstreamer

Medium severity, CVSS 6.6. EPSS: 0.1% chance of exploitation in the next 30 days.

A flaw was found in GStreamer gst-plugins-good (avidemux). When parsing FUJIFILM metadata in an AVI strd chunk, gst_avi_demux_parse_strd() decrements a remaining-length counter by fixed offsets (98 and 10 bytes) without verifying sufficient data remains. For crafted strd payloads of exactly 106 or 107 bytes, the counter underflows to a very large unsigned value, causing subsequent null-terminated string scanning to read far beyond the allocated heap buffer. Date-format normalization may also write beyond the buffer end. Confirmed impacts include heap out-of-bounds read, out-of-bounds write, heap information disclosure (adjacent data appearing in parsed metadata), and application crash/denial of service. The avidemux element is auto-plugged by playbin, decodebin, and gst-discoverer, so opening or previewing a crafted AVI is sufficient to trigger the issue. Fixed upstream in gst-plugins-good 1.28.6 (GStreamer-SA-2026-0072).

Affected products

• Gstreamer Gstreamer: up to and including 1.28.6
• Red Hat Enterprise Linux: version 7.0 only; version 8.0 only; version 9.0 only; version 10.0 only

Published 2026-08-12. Last modified 2026-09-23.