Thanks to visit codestin.com
Credit goes to github.com

Skip to content

New fdAT handling code likely missing check for critical chunks #718

New issue
New issue
Open
Open
New fdAT handling code likely missing check for critical chunks#718
@fintelia

Description

@fintelia
fintelia
opened on Jul 4, 2025

The newly added APNG code within png_read_IDAT_data includes a check for IEND chucks in the middle of a fdAT sequence, but as far as I can tell, will just produce a warning if an IDAT, IHDR, or even an unrecognized critical chunk were included there:

libpng/pngrutil.c

Lines 4399 to 4407 in 7e69b66

if (png_ptr->chunk_name == png_IEND)
png_error(png_ptr, "Not enough image data");
if (png_ptr->chunk_name != png_fdAT)
{
png_warning(png_ptr,
"Ignoring unexpected chunk in APNG sequence");
bytes_to_skip = png_ptr->idat_size;
continue;
}

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions