An issue was discovered in libSDL2.a in Simple DirectMedia Layer (SDL) 2.0.9 when used in conjunction with libSDL2_image.a in SDL2_image 2.0.4. There is an out-of-bounds read in the SDL function SDL_FreePalette_REAL at video/SDL_pixels.c.
https://usn.ubuntu.com/4238-1/
https://lists.debian.org/debian-lts-announce/2019/07/msg00026.html
https://lists.debian.org/debian-lts-announce/2019/07/msg00021.html
https://bugzilla.libsdl.org/show_bug.cgi?id=4627
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00029.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00012.html