Heap use-after-free in ODF number-format blank-width parsing
Summary
| CVE | CVE-2026-6040 |
|---|---|
| State | PUBLISHED |
| Assigner | Document Fdn. |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-15 18:16:36 UTC |
| Updated | 2026-07-15 01:16:46 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 5.4 MEDIUM from [email protected]
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
EPSS: 0.001140000 probability, percentile 0.017250000 (date 2026-07-16)
Problem Types: CWE-416 | CWE-787 | CWE-825 | CWE-416 CWE-416 Use After Free | CWE-787 CWE-787 Out-of-bounds Write | CWE-825 Expired Pointer Dereference
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | CVSS | 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 |
| 3.1 | ADP | CVSS | 7.3 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 7.3 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
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 v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | The Document Foundation | LibreOffice | affected 25.8 < 25.8.7 25.8 series | Not specified |
| CNA | The Document Foundation | LibreOffice | affected 26.2 < 26.2.3 26.2 series | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-6040 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| www.libreoffice.org/about-us/security/advisories/cve-2026-6040 | [email protected] | www.libreoffice.org | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6040.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Anthropic (automated discovery using Claude) (en)
CNA: Trail of Bits (triage and validation) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-06-15T18:01:31.633Z | Reported to Red Hat. |
| ADP | 2026-06-15T16:21:53.903Z | Made public. |
Workarounds
ADP: Users should exercise caution and avoid opening untrusted OpenDocument Format (ODF) files.