gdImageGd2Ptr in gd_gd2.c in the GD Graphics Library (aka LibGD) through 2.3.2 has a double free. NOTE: the vendor's position is "The GD2 image format is a proprietary image format of libgd. It has to be regarded as being obsolete, and should only be used for development and testing purposes.
read_header_tga in gd_tga.c in the GD Graphics Library (aka LibGD) through 2.3.2 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted TGA file.
In the GD Graphics Library (aka LibGD) through 2.2.5, there is a heap-based buffer over-read in tiffWriter in gd_tiff.c. NOTE: the vendor says "In my opinion this issue should not have a CVE, since the GD and GD2 formats are documented to be 'obsolete, and should only be used for development and testing purposes.'
gdImageClone in gd.c in libgd 2.1.0-rc2 through 2.2.5 has a NULL pointer dereference allowing attackers to crash an application via a specific function call sequence. Only affects PHP when linked with an external libgd (not bundled).
Double free vulnerability in the gdImagePngPtr function in libgd2 before 2.2.5 allows remote attackers to cause a denial of service via vectors related to a palette with no colors.