SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-63276

A stack buffer overflow existed in that conversion.

MEDIUM 5.4EPSS 0.19%

Does this matter?

Lower severity and a low EPSS score (0.19%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0
5.4 MEDIUMCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.19% probability · 9th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Source
security@documentfoundation.org
EPSS trend
0%3%5%23 September 2026: 0.17%26 October 2026: 0.19%23 September 202626 October 2026

EPSS moved from 0.2% on 23 September 2026 to 0.2% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.