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Fencer Vulns
medium 5.4

CVE-2026-63275 json

Stack buffer overflow in CFF font hint handling

published 2026-09-22 48 d ago modified 2026-09-22 47 d ago also EUVD-2026-84355

cvss
5.4
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

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.

Patch / fix

  • The Document Foundation LibreOffice < 26.2.5
  • libreoffice Debian 13 4:25.2.3-2+deb13u7
  • libreoffice Debian 14 4:26.2.5.2-1

debian advisories DEBIAN-CVE-2026-63275

  • libreoffice Ubuntu 22.04 LTS 1:7.3.7-0ubuntu0.22.04.13
  • libreoffice Ubuntu 24.04 LTS 4:24.2.7-0ubuntu0.24.04.7
  • libreoffice Ubuntu 26.04 LTS 4:26.2.6.3-0ubuntu0.26.04.2

ubuntu advisories UBUNTU-CVE-2026-63275

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libreoffice RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-af RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-bg RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-ca RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-cs RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-da RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-de RHEL 9 1:7.1.8.1-15.el9_8.3
  • autocorr-el RHEL 9 1:7.1.8.1-15.el9_8.3

red hat advisories RHSA-2026:82013

  • sac AlmaLinux 8 1.3-29.el8_10
  • flute AlmaLinux 8 1.3.0-19.OOo31.el8_10
  • libbase AlmaLinux 8 1.1.3-21.el8_10
  • libfonts AlmaLinux 8 1.1.3-23.el8_10
  • liblayout AlmaLinux 8 0.2.10-19.el8_10
  • libloader AlmaLinux 8 1.1.3-19.el8_10
  • libformula AlmaLinux 8 1.1.3-20.el8_10
  • autocorr-af AlmaLinux 8 1:7.1.8.1-3.el8_10.alma.1

almalinux advisories ALSA-2026:88164ALSA-2026:82013

  • flute Rocky Linux 8 1.3.0-19.OOo31.el8_10
  • libbase Rocky Linux 8 1.1.3-21.el8_10
  • libfonts Rocky Linux 8 1.1.3-23.el8_10
  • liblayout Rocky Linux 8 0.2.10-19.el8_10
  • libloader Rocky Linux 8 1.1.3-19.el8_10
  • libformula Rocky Linux 8 1.1.3-20.el8_10
  • libreoffice Rocky Linux 8 1:7.1.8.1-3.el8_10
  • librepository Rocky Linux 8 1.1.3-19.el8_10

rocky linux advisories RLSA-2026:88164RLSA-2026:82013

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-63275 updated cvss 7.3

libreoffice: stack buffer overflow in CFF font hint handling

  • Red Hat Enterprise Linux 6 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +60 more
    affected: workaround, no fix planned “Do not open documents from unknown or untrusted sources with LibreOffice.”
  • Red Hat Enterprise Linux 7 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +105 more
    affected: workaround, no fix available “Do not open documents from unknown or untrusted sources with LibreOffice.”
  • Red Hat Enterprise Linux AppStream (v. 8) sac 1.3-29.el8_10, libbase 1.1.3-21.el8_10, libfonts 1.1.3-23.el8_10, libloader 1.1.3-19.el8_10, libformula 1.1.3-20.el8_10, liblayout 0.2.10-19.el8_10, +107 more
    fixed: vendor fix “Do not open documents from unknown or untrusted sources with LibreOffice.” RHSA-2026:88164
  • Red Hat Enterprise Linux AppStream (v. 9) autocorr-af 7.1.8.1-15.el9_8.3, autocorr-bg 7.1.8.1-15.el9_8.3, autocorr-ca 7.1.8.1-15.el9_8.3, autocorr-cs 7.1.8.1-15.el9_8.3, autocorr-da 7.1.8.1-15.el9_8.3, autocorr-de 7.1.8.1-15.el9_8.3, +100 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libreoffice-sdk 7.1.8.1-15.el9_8.3
    fixed: vendor fix “Do not open documents from unknown or untrusted sources with LibreOffice.” RHSA-2026:82013
  • Red Hat Enterprise Linux CRB (v. 8) libreoffice-sdk 7.1.8.1-3.el8_10
    fixed: vendor fix “Do not open documents from unknown or untrusted sources with LibreOffice.” RHSA-2026:88164

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
48 d ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.4 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
CNA 4.0 5.4 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/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

Affected products

  • The Document Foundation LibreOffice

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.