Buffer overflow in Happyseafox Sail

CVE-2026-27168

SAIL is a cross-platform library for loading and saving images with support for animation, metadata, and ICC profiles. All versions are vulnerable to Heap-based Buffer Overflow through the XWD parser's use of the bytes_per_line value. The value os read directly from the file as the read size in io->strict_read(), and is never compared to the actual size of the destination buffer. An attacker can provide an XWD file with an arbitrarily large bytes_per_line, causing a massive write operation beyond the buffer heap allocated for the image pixels. The issue did not have a fix at the time of publication.

Vulnerability class: Buffer Overflow

EPSS: 0.004 (32.4th percentile) — read the EPSS interpretation.