CVE-2026-63276 — Stack buffer overflow in CFF to Type 1 font conversion
LibreOffice converts CFF fonts to Type 1 when it subsets a font, which happens when a document is exported to PDF, and CFF fonts may be embedded in documents. A stack buffer ove…
Published: 2026-09-22 · CVSS: 5.4 · CVSS 4.0
LibreOffice converts CFF fonts to Type 1 when it subsets a font, which happens when a document is exported to PDF, and CFF fonts may be embedded in documents. A stack buffer overflow existed in that conversion. The converted operators were written into a fixed size buffer with no check that they still fit, so a glyph emitting many operators wrote past the end of the buffer. In fixed versions the remaining capacity is tracked and the conversion stops when it is used up.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7