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ALT-PU-2026-14024: package `perl-Imager` update to version 1.034-alt2

Imager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8. With a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row. The same reader ships bundled in the Imager distribution. Reading an attacker-supplied PNG through Imager->read() corrupts the heap, which can crash the process.

Imager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8. With a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row. The same reader ships bundled in the Imager distribution. Reading an attacker-supplied PNG through Imager->read() corrupts the heap, which can crash the process.

Imager::File::PNG versions from 1.003 before 1.004 for Perl write past ...

Imager versions from 0.45_02 before 1.035 for Perl read outside the EXIF block via unchecked start offsets in tiff_load_ifd. tiff_load_ifd() validates an IFD entry's data by checking that `entry->offset + entry->size` stays within the EXIF block, and never checks the start offset itself. Where that sum is not the real end of the data, the check passes with the entry starting outside the block. Through 1.032 `entry->offset` is a plain int, so on the usual two's-complement implementations an offset with the high bit set converts to negative and the sum can land back inside the block. From 1.033 the field is a size_t and the addition wraps only where size_t is 32 bits. The IFD's own start offset is checked the same way and wraps where unsigned long is 32 bits, which includes 64-bit Windows. Any caller of Imager->read() on an attacker-supplied image may receive EXIF tags holding bytes from outside the block, or crash the process.

Imager versions from 0.45_02 before 1.035 for Perl read outside the EXIF block via unchecked start offsets in tiff_load_ifd. tiff_load_ifd() validates an IFD entry's data by checking that `entry->offset + entry->size` stays within the EXIF block, and never checks the start offset itself. Where that sum is not the real end of the data, the check passes with the entry starting outside the block. Through 1.032 `entry->offset` is a plain int, so on the usual two's-complement implementations an offset with the high bit set converts to negative and the sum can land back inside the block. From 1.033 the field is a size_t and the addition wraps only where size_t is 32 bits. The IFD's own start offset is checked the same way and wraps where unsigned long is 32 bits, which includes 64-bit Windows. Any caller of Imager->read() on an attacker-supplied image may receive EXIF tags holding bytes from outside the block, or crash the process.

Imager versions from 0.45_02 before 1.035 for Perl read outside the EX ...