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CVE-2026-73639 (GCVE-0-2026-73639)

Vulnerability from cvelistv5 – Published: 2026-09-17 21:18 – Updated: 2026-09-18 00:18
VLAI
Title
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
Summary
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.
Severity
No CVSS data available.
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Affected: 1.003 , < 1.004 (custom)
Affected: 1.034 , < 1.035 (custom)
Credits
Alexander Bluhm (bluhm)
Show details on NVD website
To clipboard 

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