CVE-2026-18495

Name	CVE-2026-18495
Description	A flaw was found in libtiff. A heap-buffer overflow vulnerability exists in the `tiff2pdf` utility due to an integer truncation error when processing crafted BigTIFF files. An attacker can provide a specially crafted BigTIFF file, causing a 64-bit `StripByteCounts` value to be truncated to a 32-bit integer. This leads to an undersized memory allocation and a subsequent out-of-bounds memory copy, resulting in a crash and severe memory corruption.
Source	CVE (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 Package	Release	Version	Status
tiff (PTS)	bookworm, bookworm (security)	4.5.0-6+deb12u4	vulnerable
	trixie, trixie (security)	4.7.0-3+deb13u3	vulnerable
	forky, sid	4.7.2-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
tiff	source	(unstable)	4.7.1-1

Notes

https://bugzilla.redhat.com/show_bug.cgi?id=2531414
https://gitlab.com/libtiff/libtiff/-/merge_requests/729
Fixed by: https://gitlab.com/libtiff/libtiff/-/commit/67fd283d276f09db54dc39b9ef7b979d4b45c4b1 (v4.7.1rc1)