{"id":"DEBIAN-CVE-2026-73639","details":"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-\u003eread() corrupts the heap, which can crash the process.","modified":"2026-09-23T09:00:10.037837301Z","published":"2026-09-17T22:17:03.763Z","upstream":["CVE-2026-73639"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-73639"}],"affected":[{"package":{"name":"libimager-perl","ecosystem":"Debian:12","purl":"pkg:deb/debian/libimager-perl?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.019+dfsg-1","1.019+dfsg-2","1.020+dfsg-1","1.022+dfsg-1","1.023+dfsg-1","1.024+dfsg-1","1.024+dfsg-2","1.025+dfsg-1","1.027+dfsg-1","1.028+dfsg-1","1.029+dfsg-1","1.030+dfsg-1","1.031+dfsg-1","1.032+dfsg-1","1.033+dfsg-1","1.034+dfsg-1","1.034+dfsg-2","1.035+dfsg-1","1.036+dfsg-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-73639.json"}},{"package":{"name":"libimager-perl","ecosystem":"Debian:13","purl":"pkg:deb/debian/libimager-perl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.027+dfsg-1","1.028+dfsg-1","1.029+dfsg-1","1.030+dfsg-1","1.031+dfsg-1","1.032+dfsg-1","1.033+dfsg-1","1.034+dfsg-1","1.034+dfsg-2","1.035+dfsg-1","1.036+dfsg-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-73639.json"}},{"package":{"name":"libimager-perl","ecosystem":"Debian:14","purl":"pkg:deb/debian/libimager-perl?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.035+dfsg-1"}]}],"versions":["1.027+dfsg-1","1.028+dfsg-1","1.029+dfsg-1","1.030+dfsg-1","1.031+dfsg-1","1.032+dfsg-1","1.033+dfsg-1","1.034+dfsg-1","1.034+dfsg-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-73639.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"}]}