CVE-2026-6040
Heap use-after-free in ODF number-format blank-width parsing
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
5.4
Heap use-after-free in ODF number-format blank-width parsing
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
CVE-2026-6040- CVSS 4.0
- 5.4 Medium
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 - CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-416, CWE-787, CWE-825
- Updated
- 2026-11-02
EUVDEUVD-2026-36735
5.4
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
EUVD-2026-36735- CVSS 4.0
- 5.4 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pp4w-c8m6-4xvf
5.4
A heap use-after-free existed when importing the blank-width characters of an ODF number format....
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
GHSA-pp4w-c8m6-4xvf- CVSS 4.0
- 5.4 Medium
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 - CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-416, CWE-825
- Updated
- 2026-11-02
NVD
5.4
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
CVE-2026-6040- CVSS 4.0
- 5.4 Medium
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 - CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-416, CWE-787, CWE-825
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-6040
5.4
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
DEBIAN-CVE-2026-6040- CVSS 4.0
- 5.4 Medium
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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-6040
5.4
A heap use-after-free existed when importing the blank-width characters of an ODF number format. A position value read from the document was not checked against the length of the format-code string, so a malformed number format could be processed against memory outside that string. In fixed versions the position is bounds-checked before use.
- Record
UBUNTU-CVE-2026-6040- CVSS 4.0
- 5.4 Medium
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 - CVSS 3.1
- 7.3 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVMGASA-2026-0259 No score
Updated libreoffice packages fix security vulnerabilities
The updated packages fix security vulnerabilities: Heap buffer overflow in DXF polyline import. (CVE-2026-6039) Heap use-after-free in ODF number-format blank-width parsing. (CVE-2026-6040) Heap buffer overflow in EMF+ gradient brush import. (CVE-2026-6045) Stack buffer overflow in PPT presentation import. (CVE-2026-8356) Heap buffer overflow in Calc formula compilation. (CVE-2026-8357) Heap buffer overflow in spreadsheet tracked-changes import. (CVE-2026-8358)
- Record
MGASA-2026-0259- Updated
- 2026-11-02
OSVopenSUSE-SU-2026:22216-1 No score
Security update for libreoffice
This update for libreoffice fixes the following issues:
Changes in libreoffice:
-
Upgrade to 26.8.1.1.
-
Perfect spec file sync between Factory, SLE and Leap 16.X.
-
Update to LibreOffice 26.2.5.1 (was 25.2.5.2).
-
Fix the following security issues:
- CVE-2026-6039 (bsc#1268494): Denial of Service via a specially crafted DXF polyline import.
- CVE-2026-6045 (bsc#1268497): Heap buffer overflow via crafted EMF+ graphics import.
- CVE-2026-6047 (bsc#1268504): Denial of Service via heap buffer overflow in OOXML document processing.
- CVE-2026-8356 (bsc#1268522): Denial of Service via a specially crafted PPT file.
- CVE-2026-6040 (bsc#1268527): Heap use-after-free when importing the blank-width characters of an ODF number format.
- CVE-2026-8357 (bsc#1268528): Heap buffer overflow in Calc formula compilation.
- CVE-2026-8358 (bsc#1268529): Heap buffer overflow in spreadsheet tracked-changes import.
- CVE-2026-4430 (bsc#1264357): Out-of-bounds write via crafted OOXML documents with mismatched encryption salt parameters.
- Record
openSUSE-SU-2026:22216-1- Updated
- 2026-11-04
OSVSUSE-SU-2026:3140-1 No score
Security update for libreoffice
This update for libreoffice fixes the following issues:
Update to LibreOffice 26.2.5.1.
Security issues fixed:
- CVE-2026-4430: out-of-bounds write via crafted OOXML documents with mismatched encryption salt parameters (bsc#1264357).
- CVE-2026-6039: denial of service via specially crafted DXF polyline import (bsc#1268494).
- CVE-2026-6040: heap use-after-free when importing the blank-width characters of an ODF number format (bsc#1268527).
- CVE-2026-6045: heap buffer overflow via crafted EMF+ graphics import (bsc#1268497).
- CVE-2026-6047: denial of service via heap buffer overflow in OOXML document processing (bsc#1268504).
- CVE-2026-8356: denial of service via a specially crafted PPT file (bsc#1268522).
- CVE-2026-8357: heap buffer overflow in Calc formula compilation (bsc#1268528).
- CVE-2026-8358: heap buffer overflow in spreadsheet tracked-changes import (bsc#1268529).
- CVE-2026-50593: graphite2: out-of-bounds write via Graphite actions (bsc#1267735).
Other updates and bugfixes:
- Update to LibreOffice 26.2.5.1.
- Update bundled dependencies:
fontconfig2.17.1 -> 2.18.0graphite2-minimal1.3.14 -> 1.3.15libcmis0.6.2 -> 0.6.3libgpg-error1.59 -> 1.61lxml6.1.0 -> 6.1.1md4c0.5.2 -> 0.5.3poppler26.04.0 -> 26.06.0sqlite-amalgamation3530000 -> 3530100xmlsec11.3.9 -> 1.3.11
- Update bundled dependencies:
- Update to LibreOffice 26.2.3.2 (PED-16098).
- Upgraded dependencies:
boost: 1_88_0 -> 1_89_0freetype: 2.14.1 -> 2.14.3harfbuzz: 12.3.0 -> 12.3.2icu4c: 77_1 -> 78.3libgpg-error: 1.56 -> 1.59liborcus: 0.20.1 -> 0.21.0pdfium: 7012 -> 7471poppler: 25.12.0 -> 26.04.0skia: m136 -> m142
- New bundled sources:
afdko4.0.3antlr4-cpp-runtime4.13.2fast_float8.2.2libffi3.5.2lxml6.1.0md4c0.5.2meson1.8.3Python3.12.13sqlite3530000xmlsec11.3.9xz5.8.3
- Upgraded dependencies:
- Add
patch, required to build the bundled Python on all architectures. - Bundling a specific Python is now required as the one we ship (3.6) is too old to build
harfbuzz.
- Record
SUSE-SU-2026:3140-1- Updated
- 2026-11-02
OSVUSN-8534-1 No score
libreoffice vulnerabilities
It was discovered that LibreOffice incorrectly handled importing DXF drawings. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-6039)
It was discovered that LibreOffice incorrectly handled certain ODF number formats. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-6040)
It was discovered that LibreOffice incorrectly handled importing EMF+ graphics. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-6045)
It was discovered that LibreOffice incorrectly handled importing PPT presentations. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-8356)
It was discovered that LibreOffice Calc incorrectly handled compiling certain formulas. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possily execute arbitrary code. (CVE-2026-8357)
It was discovered that LibreOffice Calc incorrectly handled importing spreadsheet tracked changes. An attacker could use this issue to cause LibreOffice to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-8358)
- Record
USN-8534-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libreofficeDebian:13 |
before 4:25.2.3-2+deb13u5, plus listed versions 4:25.2.3-24:25.2.3-2+deb13u14:25.2.3-2+deb13u24:25.2.3-2+deb13u2~bpo12+14:25.2.3-2+deb13u34:25.2.3-2+deb13u3~bpo12+14:25.2.3-2+deb13u44:25.2.3-2+deb13u5~bpo12+1 |
4:25.2.3-2+deb13u5 |
libreofficeDebian:14 |
before 4:26.2.3.2-2, plus listed versions 4:25.2.3-24:25.8.0-14:25.8.0-1~bpo13+14:25.8.0~alpha1-14:25.8.0~alpha1-2 Show 45 moreShow less4:25.8.0~beta1-14:25.8.0~rc1-14:25.8.0~rc1-24:25.8.0~rc2-14:25.8.0~rc2-24:25.8.0~rc3-14:25.8.0~rc4-14:25.8.0~rc4-24:25.8.1-14:25.8.1-1~bpo13+14:25.8.1~rc1-14:25.8.2-14:25.8.2-24:25.8.2-34:25.8.2-3~bpo13+14:25.8.2~rc1-14:25.8.2~rc2-14:25.8.3-14:25.8.3-1+ports4:25.8.3-1~bpo13+14:25.8.3~rc1-14:25.8.3~rc2-14:25.8.4-14:25.8.4-1~bpo13+14:26.2.0-14:26.2.0-1~bpo13+14:26.2.0~alpha1-14:26.2.0~alpha1-24:26.2.0~alpha1-34:26.2.0~beta1-14:26.2.0~rc1-14:26.2.0~rc2-14:26.2.0~rc3-14:26.2.1-14:26.2.1-1~bpo13+14:26.2.1~rc1-14:26.2.1~rc2-14:26.2.2.1-14:26.2.2.1-24:26.2.2.2-14:26.2.2.2-24:26.2.2.2-34:26.2.2.2-3~bpo13+14:26.2.3.1-14:26.2.3.2-1 |
4:26.2.3.2-2 |
libreofficeMageia:10 From an advisory covering 6 CVEs |
before 26.2.4.2-1.mga10 | 26.2.4.2-1.mga10 |
libreofficeMageia:9 From an advisory covering 6 CVEs |
before 24.2.7.2-1.5.mga9 | 24.2.7.2-1.5.mga9 |
libreofficeSUSE:Linux Enterprise Module for Package Hub 15 SP7 From an advisory covering 9 CVEs |
before 26.2.5.1-150500.20.37.1 | 26.2.5.1-150500.20.37.1 |
libreofficeSUSE:Linux Enterprise Workstation Extension 15 SP7 From an advisory covering 9 CVEs |
before 26.2.5.1-150500.20.37.1 | 26.2.5.1-150500.20.37.1 |
libreofficeUbuntu:24.04:LTS |
before 4:24.2.7-0ubuntu0.24.04.6, plus listed versions 4:7.6.2-0ubuntu14:7.6.3~rc1-0ubuntu24:7.6.3-0ubuntu34:7.6.4-0ubuntu14:7.6.4-0ubuntu3 Show 17 moreShow less4:24.2.0~rc1-0ubuntu14:24.2.1~rc1-0ubuntu14:24.2.1~rc2-0ubuntu14:24.2.2~rc2-0ubuntu14:24.2.2-0ubuntu14:24.2.3-0ubuntu0.24.04.14:24.2.3-0ubuntu0.24.04.24:24.2.4-0ubuntu0.24.04.14:24.2.4-0ubuntu0.24.04.24:24.2.5-0ubuntu0.24.04.14:24.2.5-0ubuntu0.24.04.24:24.2.6-0ubuntu0.24.04.14:24.2.7-0ubuntu0.24.04.14:24.2.7-0ubuntu0.24.04.24:24.2.7-0ubuntu0.24.04.34:24.2.7-0ubuntu0.24.04.44:24.2.7-0ubuntu0.24.04.5 |
4:24.2.7-0ubuntu0.24.04.6 |
libreofficeUbuntu:25.10 |
All versions, plus listed versions 4:25.2.2-0ubuntu14:25.2.3-0ubuntu14:25.2.3-0ubuntu34:25.2.4~rc3-0ubuntu14:25.2.5~rc1-0ubuntu1 Show 12 moreShow less4:25.2.5-0ubuntu14:25.8.0~rc2-0ubuntu14:25.8.0~rc2-0ubuntu24:25.8.0~rc3-0ubuntu14:25.8.0~rc4-0ubuntu14:25.8.1~rc1-0ubuntu14:25.8.2-0ubuntu0.25.10.14:25.8.3-0ubuntu0.25.10.14:25.8.4-0ubuntu0.25.10.14:25.8.5-0ubuntu0.25.10.14:25.8.6-0ubuntu0.25.10.14:25.8.7-0ubuntu0.25.10.1 |
None known |
libreofficeUbuntu:26.04:LTS |
before 4:26.2.4.2-0ubuntu0.26.04.2, plus listed versions 4:25.8.1~rc1-0ubuntu14:25.8.3-0ubuntu14:25.8.4~rc1-0ubuntu24:25.8.4~rc1-0ubuntu34:25.8.4~rc2-0ubuntu1 Show 4 moreShow less4:26.2.1~rc2-0ubuntu14:26.2.2.2-0ubuntu14:26.2.3.2-0ubuntu0.26.04.14:26.2.4.2-0ubuntu0.26.04.1 |
4:26.2.4.2-0ubuntu0.26.04.2 |
libreofficeUbuntu:22.04:LTS From an advisory covering 6 CVEs |
before 1:7.3.7-0ubuntu0.22.04.12, plus listed versions 1:7.2.1-0ubuntu31:7.2.2-0ubuntu0.21.10.11:7.2.3~rc2-0ubuntu11:7.2.4-0ubuntu11:7.2.5~rc1-0ubuntu2 Show 23 moreShow less1:7.2.5~rc2-0ubuntu11:7.3.1~rc2-0ubuntu11:7.3.1~rc3-0ubuntu11:7.3.2~rc1-0ubuntu21:7.3.2~rc2-0ubuntu11:7.3.2-0ubuntu11:7.3.2-0ubuntu21:7.3.3-0ubuntu0.22.04.11:7.3.4-0ubuntu0.22.04.11:7.3.5-0ubuntu0.22.04.11:7.3.6-0ubuntu0.22.04.11:7.3.6-0ubuntu0.22.04.21:7.3.7-0ubuntu0.22.04.11:7.3.7-0ubuntu0.22.04.21:7.3.7-0ubuntu0.22.04.31:7.3.7-0ubuntu0.22.04.41:7.3.7-0ubuntu0.22.04.51:7.3.7-0ubuntu0.22.04.61:7.3.7-0ubuntu0.22.04.71:7.3.7-0ubuntu0.22.04.81:7.3.7-0ubuntu0.22.04.91:7.3.7-0ubuntu0.22.04.101:7.3.7-0ubuntu0.22.04.11 |
1:7.3.7-0ubuntu0.22.04.12 |
libreofficeUbuntu:24.04:LTS From an advisory covering 6 CVEs |
before 4:24.2.7-0ubuntu0.24.04.6, plus listed versions 4:7.6.2-0ubuntu14:7.6.3~rc1-0ubuntu24:7.6.3-0ubuntu34:7.6.4-0ubuntu14:7.6.4-0ubuntu3 Show 17 moreShow less4:24.2.0~rc1-0ubuntu14:24.2.1~rc1-0ubuntu14:24.2.1~rc2-0ubuntu14:24.2.2~rc2-0ubuntu14:24.2.2-0ubuntu14:24.2.3-0ubuntu0.24.04.14:24.2.3-0ubuntu0.24.04.24:24.2.4-0ubuntu0.24.04.14:24.2.4-0ubuntu0.24.04.24:24.2.5-0ubuntu0.24.04.14:24.2.5-0ubuntu0.24.04.24:24.2.6-0ubuntu0.24.04.14:24.2.7-0ubuntu0.24.04.14:24.2.7-0ubuntu0.24.04.24:24.2.7-0ubuntu0.24.04.34:24.2.7-0ubuntu0.24.04.44:24.2.7-0ubuntu0.24.04.5 |
4:24.2.7-0ubuntu0.24.04.6 |
libreofficeUbuntu:26.04:LTS From an advisory covering 6 CVEs |
before 4:26.2.4.2-0ubuntu0.26.04.2, plus listed versions 4:25.8.1~rc1-0ubuntu14:25.8.3-0ubuntu14:25.8.4~rc1-0ubuntu24:25.8.4~rc1-0ubuntu34:25.8.4~rc2-0ubuntu1 Show 4 moreShow less4:26.2.1~rc2-0ubuntu14:26.2.2.2-0ubuntu14:26.2.3.2-0ubuntu0.26.04.14:26.2.4.2-0ubuntu0.26.04.1 |
4:26.2.4.2-0ubuntu0.26.04.2 |
libreofficeopenSUSE:Leap 16.0 From an advisory covering 8 CVEs |
before 26.8.1.1-bp160.1.1 | 26.8.1.1-bp160.1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| affected, aliases, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-6040 is a medium vulnerability (CVSS 5.4) in Red Hat Enterprise Linux 6, published June 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.16%, the 5th percentile. Fixed in libreoffice 4:25.2.3-2+deb13u5.
References
libreoffice.org/about-us/security/advisories/cve-2026-6040
access.redhat.com/security/cve/CVE-2026-6040
bugzilla.redhat.com/show_bug.cgi?id=2488966
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6040.json
nvd.nist.gov/vuln/detail/CVE-2026-6040
github.com/advisories/GHSA-pp4w-c8m6-4xvf
Show 32 moreShow less
security-tracker.debian.org/tracker/CVE-2026-6040
advisories.mageia.org/MGASA-2026-0259.html
bugs.mageia.org/show_bug.cgi?id=35709
lists.debian.org/debian-security-announce/2026/msg00257.html
libreoffice.org/security
suse.com/support/update/announcement/2026/suse-su-20263140-1
bugzilla.suse.com/1264357
bugzilla.suse.com/1267735
bugzilla.suse.com/1268494
bugzilla.suse.com/1268497
bugzilla.suse.com/1268504
bugzilla.suse.com/1268522
bugzilla.suse.com/1268527
bugzilla.suse.com/1268528
bugzilla.suse.com/1268529
suse.com/security/cve/CVE-2026-4430
suse.com/security/cve/CVE-2026-50593
suse.com/security/cve/CVE-2026-6039
suse.com/security/cve/CVE-2026-6040
suse.com/security/cve/CVE-2026-6045
suse.com/security/cve/CVE-2026-6047
suse.com/security/cve/CVE-2026-8356
suse.com/security/cve/CVE-2026-8357
suse.com/security/cve/CVE-2026-8358
ubuntu.com/security/CVE-2026-6040
cve.org/CVERecord?id=CVE-2026-6040
ubuntu.com/security/notices/USN-8534-1
ubuntu.com/security/CVE-2026-6039
ubuntu.com/security/CVE-2026-6045
ubuntu.com/security/CVE-2026-8356
ubuntu.com/security/CVE-2026-8357
ubuntu.com/security/CVE-2026-8358
Left out here: 1 version. The JSON record has them.