Quick answers
- Is CVE-2026-6040 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-6040 being exploited in the wild.
- How severe is CVE-2026-6040?
- Informational severity, with a CVSS score of 5.4, published 15 June 2026.
- Which products and versions are affected?
- The Document Foundation LibreOffice.
- Is there a fix for CVE-2026-6040?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-6040 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2026-6040?
- Check whether you run The Document Foundation LibreOffice. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A heap use-after-free vulnerability (CWE-416) and out-of-bounds write (CWE-787) exist in LibreOffice's ODF import component. The flaw is triggered when processing the blank-width characters of an ODF number format. A position value read from the document is not validated against the length of the format-code string, allowing the application to process memory outside the intended buffer. An attacker can exploit this by providing a malformed document that requires user interaction (opening the file). This can result in a crash (denial of service) or potentially arbitrary code execution in the context of the user. Fixed versions implement proper bounds-checking for the position value.
Affected products
- The Document Foundation LibreOffice
Timeline
- 2026-06-15: disclosed
- 2026-06-15: advisory