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Fencer Intel
medium 5.4

CVE-2026-6047 json

Heap buffer overflow in OOXML text box element import

published 4mo ago modified 17d ago also EUVD-2026-36737

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 4%
public exploits
0
none known

Summary

LibreOffice can import documents in the OOXML format (DOCX). A heap buffer overflow existed when replaying deferred parser events for a text box element. A handler object was assumed to be of one type and written to at that type's field layout, but it could be a smaller object, so the write landed past the end of the allocation. In fixed versions the type is checked before the write.

Patch / fix

  • The Document Foundation LibreOffice < 25.8.7, < 26.2.3
  • libreoffice Debian 14 4:26.2.3.2-2

debian advisories DEBIAN-CVE-2026-6047

  • libreoffice Ubuntu 26.04 LTS 4:26.2.4.2-0ubuntu0.26.04.2

ubuntu advisories UBUNTU-CVE-2026-6047

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 SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 26.2.5.1-150500.20.37.1

suse advisories SUSE-SU-2026:3140-1

  • libreoffice openSUSE Leap 16.0 26.8.1.1-bp160.1.1

opensuse advisories openSUSE-SU-2026:22216-1

Is CVE-2026-6047 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-6047 updated cvss 5.0

libreoffice: LibreOffice: Denial of service via heap buffer overflow in OOXML document processing

  • Red Hat Enterprise Linux 6 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +60 more Red Hat Enterprise Linux 7 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +105 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +98 more Red Hat Enterprise Linux 9 autocorr-af, autocorr-bg, autocorr-ca, autocorr-cs, autocorr-da, autocorr-de, +101 more
    affected: workaround, no fix available “Fix deferred”

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
4mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).

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
  • CWE-787 Out-of-bounds Write
  • CWE-843 Access of Resource Using Incompatible Type

References

Sources

Fencer Intel 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.