CVE-2026-63276
Stack buffer overflow in CFF to Type 1 font conversion
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| Vendor | the document foundation |
| Product | libreoffice |
| Published | Sep 22, 2026 |
| Last Updated | Sep 22, 2026 |
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Affected Versions
The Document Foundation / LibreOffice
26.2 < < 26.2.5
References
Credits
Claude, found by Anthropic using agents to study the security of open-source projects Ada Logics, validating and reporting Caolán McNamara of Collabora Productivity