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Fencer Vulns
medium 5.4

CVE-2026-63274 json

Heap buffer overflow in PDF import stream handling

published 2026-09-22 47 d ago modified 2026-09-28 41 d ago also EUVD-2026-84354

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 9%
public exploits
0
none known

Summary

LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing a stream object. The length of the stream was taken from the object's own dictionary and was not checked against the number of bytes actually present, so copying the stream read and wrote past the end of the buffer holding it. In fixed versions the declared length is clamped to the bytes actually read.

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-2026-63274

  • 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-2026-63274

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-2026-63274 updated cvss 7.3

libreoffice: heap buffer overflow in PDF import stream 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 import PDF documents from unknown or untrusted sources with LibreOffice Draw.”
  • 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 import PDF documents from unknown or untrusted sources with LibreOffice Draw.”
  • 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 import PDF documents from unknown or untrusted sources with LibreOffice Draw.” 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 import PDF documents from unknown or untrusted sources with LibreOffice Draw.” RHSA-2026:82013
  • Red Hat Enterprise Linux CRB (v. 8) libreoffice-sdk 7.1.8.1-3.el8_10
    fixed: vendor fix “Do not import PDF documents from unknown or untrusted sources with LibreOffice Draw.” 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
47 d ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% 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.