ZLMediaKit is a streaming media service framework. the VP9 RTP payload parser in ext-codec/VP9Rtp.cpp reads multiple fields from the RTP payload based on flag bits in the first byte, without verifying that sufficient data exists in the buffer. A crafted VP9 RTP packet with a 1-byte payload (0xFF, all flags set) causes the parser to read past the end of the allocated buffer, resulting in a heap-buffer-overflow. This vulnerability is fixed with commit 435dcbcbbf700fd63b2ca9eac6cef3b5ea75169d.