Gst-plugins-bad: gst-plugins-bad: h.265 sps scc palette predictor array overflow via integer underflow in bounds computation

A flaw was found in GStreamer's gst-plugins-bad H.265 video parser. When parsing a specially crafted H.265 bitstream containing a Screen Content Coding (SCC) extension with certain palette predictor initializer settings, an integer underflow in the upper-bound computation allows the parser to accept an out-of-range value for the number of palette predictor entries. This causes the parser to write beyond the end of a fixed-size array, resulting in memory corruption and an application crash. An attacker can deliver the malformed bitstream as a local file or over a network stream such as HTTP, HLS, DASH, RTSP, RTP, or WebRTC. Successful exploitation requires the application to open or play that content, and is limited to a denial-of-service impact.