What’s Vulnerable › Vulnerabilities

CVE-2026-6040: Heap use-after-free in ODF number-format blank-width parsing

• Severity: high (CVSS 7.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-15 · updated 2026-10-25
• Weakness: CWE-416

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.

Affected products

• The Document Foundation LibreOffice: from 25.8 before < 25.8.7; from 26.2 before < 26.2.3 — fixed in < 25.8.7, < 26.2.3

How to fix

Upgrade to a fixed version: The Document Foundation LibreOffice < 25.8.7, < 26.2.3. Check the vendor advisory for mitigations.

References

• https://www.libreoffice.org/about-us/security/advisories/cve-2026-6040
• https://access.redhat.com/security/cve/CVE-2026-6040
• https://bugzilla.redhat.com/show_bug.cgi?id=2488966
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6040.json

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