Executive brief
A vulnerability exists in GStreamer, a widely used multimedia framework for processing video and audio. By tricking a user into opening a specially crafted H.264 video file, an attacker can cause the application to crash or potentially leak a small amount of memory. This could lead to service disruptions for applications relying on GStreamer for video playback or processing.
Technical details
A 1-byte heap out-of-bounds read exists in the gst_h264_parse_process_nal() function within gsth264parse.c. The vulnerability occurs when processing H.264 NAL units of type GST_H264_NAL_SLICE_EXT (type 20) used for MVC/SVC extensions. The parser attempts to check the first_mb_in_slice flag by dereferencing data at an offset equal to the header size (4 bytes) without verifying that the NAL unit contains data beyond that header. An attacker can exploit this by providing a malformed NAL unit with a size exactly equal to the header length, causing a read beyond the allocated buffer. This requires a user to open a malicious video file and can result in a Denial of Service (crash) or a single-byte information leak.
Affected products
- Red Hat gst-plugins-bad-free Enterprise Linux 6, 7, 8, 9, 10
- GStreamer GStreamer 1.x up to 1.29.1.1
Timeline
- 2026-06-22: disclosed: Reported by CoE-CNDS Lab researchers to Red Hat Bugzilla.
- 2026-06-23: advisory: NVD and Red Hat published advisory details.