CVE-2026-73639

NameCVE-2026-73639
DescriptionImager::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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
libimager-perl (PTS)bookworm1.019+dfsg-1vulnerable
trixie1.027+dfsg-1vulnerable
forky, sid1.036+dfsg-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
libimager-perlsource(unstable)1.035+dfsg-1

Notes

[trixie] - libimager-perl <no-dsa> (Minor issue)
[bookworm] - libimager-perl <postponed> (Minor issue)
https://lists.security.metacpan.org/cve-announce/msg/43640633/
https://github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88
https://github.com/tonycoz/imager/pull/567
Fixed by: https://github.com/tonycoz/imager/commit/d973bd7e8843f084e8071caa24b89545c88b1e4b (v1.035)

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