CVE-2026-63276
published 2026-09-22CVE-2026-63276: 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…
PriorityP427medium5.4CVSS 4.0
AVLACLATNPRNUIPVCLVILVAHSCNSINSANEPCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
EPSS
0.19%
8.7th percentile
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.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| libreoffice | libreoffice | — | — |
| the_document_foundation | libreoffice | >= 26.2 < < 26.2.5 | < 26.2.5 |
| ubuntu | libreoffice | — | — |
CVSS provenance
nvdv4.05.4MEDIUMCVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_ubuntu7.3HIGH
vendor_redhat5.4MEDIUM
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Ubuntu
LibreOffice vulnerabilities
vendor_ubuntu·2026-10-05·CVSS 7.3
CVE-2026-50593 [HIGH] LibreOffice vulnerabilities
Title: LibreOffice vulnerabilities
Summary: Several security issues were fixed in LibreOffice.
It was discovered that LibreOffice incorrectly handled WMF image
imports. An attacker could possibly use this issue to cause LibreOffice
to crash, resulting in a denial of service, or execute arbitrary code.
(CVE-2026-63272)
It was discovered that LibreOffice incorrectly handled PDF document
imports. An attacker could possibly use this issue to cause LibreOffice
to crash, resulting in a denial of service, or execute arbitrary code.
(CVE-2026-63273, CVE-2026-63274)
It was discovered that LibreOffice incorrectly handled CFF fonts
embedded in documents. An attacker could possibly use this issue to
cause LibreOffice to crash, resulting in a denial of service, or
execute arbitrary code. (CVE-2026-
Red Hat
libreoffice: stack buffer overflow in CFF to Type 1 font conversion
vendor_redhat·2026-09-22·CVSS 5.4
CVE-2026-63276 [MEDIUM] CWE-121 libreoffice: stack buffer overflow in CFF to Type 1 font conversion
libreoffice: stack buffer overflow in CFF to Type 1 font conversion
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.
A flaw was found in LibreOffice. When a user exports a document with crafted embedded fonts to PDF, a stack-based buffer overflow can occur during the conversion of CFF fonts to Type 1 fonts due to improper bounds checking. This issue can cause memory corr
GHSA
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.
ghsa_unreviewed·2026-09-22
CVE-2026-63276 [MEDIUM] CWE-787 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.
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.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion [fedora-all]
bugzilla·2026-09-24·CVSS 5.4
CVE-2026-63276 [MEDIUM] CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion [fedora-all]
CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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.
Bugzilla
CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion
bugzilla·2026-09-22·CVSS 5.4
CVE-2026-63276 [MEDIUM] CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion
CVE-2026-63276 libreoffice: stack buffer overflow in CFF to Type 1 font conversion
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.
2026-09-22
Published