CVE-2026-63275 PUBLISHED

Stack buffer overflow in CFF font hint handling

Assigner: Document Fdn.
Reserved: 16.07.2026 Published: 22.09.2026 Updated: 22.09.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P
CVSS Score: 5.4

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	The Document Foundation
Product	LibreOffice
Versions	Default: unknown affected from 26.2 to < 26.2.5 (excl.)

Credits

Claude, found by Anthropic using agents to study the security of open-source projects finder
Ada Logics, validating and reporting analyst
Caolán McNamara of Collabora Productivity remediation developer

References

https://www.libreoffice.org/about-us/security/advisories/cve-2026-63275

Problem Types

CWE-787 Out-of-bounds Write CWE

Impacts

CAPEC-44 Overflow Binary Resource File