Ubuntu Security Notices guidance
Vendor revision: Oct 5, 2026(CVE-2026-63279) It was discovered that LibreOffice incorrectly mitigated out-of-bounds writes via Graphite font actions.
Vulnerability intelligence
CVE-2026-63275 and is rated Medium severity with a CVSS score of 5.4. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
(CVE-2026-63279) It was discovered that LibreOffice incorrectly mitigated out-of-bounds writes via Graphite font actions.
LibreOffice can read CFF fonts, which may be embedded in documents. A stack buffer overflow existed when reading the hints of a glyph. The number of hints was checked against the wrong bound, so a glyph declaring more hints than the array can hold wrote past its end. In fixed versions the hint count is checked against the capacity the array really has.
Source: NVD