diff --git a/libavformat/rawdec.c b/libavformat/rawdec.c
index 1c9aabd6fd..5e95d10efd 100644
--- a/libavformat/rawdec.c
+++ b/libavformat/rawdec.c
@@ -45,6 +45,10 @@ int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
     if (ret < 0) {
         av_free_packet(pkt);
         return ret;
+    } else if (ret < size) {
+        /* initialize end of packet for partial reads to avoid reading
+         * uninitialized data on allowed overreads */
+        memset(pkt->data + ret, 0, FF_INPUT_BUFFER_PADDING_SIZE);
     }
     pkt->size = ret;
     return ret;