SECURITY UPDATE: out-of-bounds write when parsing composite subglyphs
of TrueType GX / variable fonts (ELSCVE-171535)
debian/patches-freetype/CVE-2025-27363.patch: reject a subglyph count
that truncates to a negative short in load_truetype_glyph before it
is used to size the outline arrays in src/truetype/ttgload.c.