Release Of FreeType 2.15 Font Engine

After a year of development, presented the release of FreeType 2.15.0, a modular font engine that provides a single API for unifying the processing and output of font data in various vector and raster formats. The project code is written in C and distributed under the BSD-like FreeType license.

Among changes:

• Added support for fifth edition of the ISO Open Font format (ISO/IEC 14496-22:2026), ported using AI from the glyph layout library HarfBuzz and other implementations. Unlike the fourth edition, released in 2019, the new version of the Open Font format now has the ability to accommodate more than 65,536 glyphs; added “GLYF” table for contours combining cubic and conical segments; a more compact version of the “VARC” table has been proposed, which allows reducing the size of variable fonts with hieroglyphs by 90%.
• In the rasterizer that provides anti-aliasing, due to dynamic memory allocation for large glyphs, the performance of drawing glyphs larger than 40 ppem has been significantly increased.
• Added an experimental driver for fonts HVF (Hierarchical Variation Font), provided by Apple and currently only works on macOS.
• The TrueType format interpreter has expanded support for ClearType text smoothing technology, which has improved the rendering quality of fonts such as ‘Comic Sans MS’, ‘Segoe’ UI’, ‘Calibri’, ‘Corbel’, ‘Constantia’, ‘Malgun Gothic’ and ‘SimSun’. The use of data from the gasp table (Grid-fitting and Scan-conversion Procedure) for smoothing and alignment to the pixel grid has been ensured, the emulation of ClearType horizontal hinting has been improved, the processing of glyph rounding instructions (ROUND) and the use of control values (CVT – Control Value Table) have been improved.
• A port has been added for the Plan 9 operating system.
• Vulnerabilities have been fixed: CVE-2026-95512 – memory exhaustion and high CPU load when processing specially designed fonts in the CID format; CVE-2026-50811 – reading from an area outside the buffer when using the TT_Get_Var_Design and T_Get_Var_Design_Coordinates functions; CVE-2026-27171 is a loopback vulnerability in old zlib inline code.