CVE-2026-63276
Medium
Description
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.
SeverityMedium
CVSS5.4
Exploit probability—
ProductLibreOffice
PublishedSep 22, 2026
First seenSep 22, 2026
Weakness typeCWE-787Out-of-bounds write
How to fix
Update
- The Document Foundation LibreOffice< 26.2.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| The Document Foundation LibreOffice | 26.2 ≤ v < < 26.2.5 | < 26.2.5 |
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