CVE-2026-73433

Description

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).

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Patch details

Severity score breakdown

CVSS version: CVSS v3.0

References

• MITRE
• NVD
• Launchpad
• Debian

Related Ubuntu Security Notices (USN)

• USN-8863-1
• GStreamer Good Plugins vulnerabilities
• 1 October 2026

Other references

• https://www.cve.org/CVERecord?id=CVE-2026-73433
• https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/12231
• https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/12241
• https://gstreamer.freedesktop.org/security/sa-2026-0072.html
• https://access.redhat.com/security/cve/CVE-2026-73433
• https://bugzilla.redhat.com/show_bug.cgi?id=2514801