Is CVE-2026-8357 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-8357 being exploited in the wild.

How severe is CVE-2026-8357?

Informational severity, with a CVSS score of 5.4, published 15 June 2026.

Which products and versions are affected?

The Document Foundation Calc Versions prior to fixed releases (e.g., 24.8.4, 25.2.1, 25.2.2, 25.2.4, 25.8.7, 26.2.3).

Is there a fix for CVE-2026-8357?

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-2026-8357 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2026-8357?

Check whether you run The Document Foundation Calc at an affected version. 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.

CVE-2026-8357: LibreOffice Calc heap buffer overflow in formula compilation

CVE-2026-8357 · Severity: info · CVSS 5.4 · Published 2026-06-15

LibreOffice Calc, a popular spreadsheet application, is vulnerable to a memory corruption issue when opening specially crafted files. An attacker could create a spreadsheet containing an extremely long and complex formula that causes the application to crash or potentially execute unauthorized code. This risk is triggered when a user simply opens the malicious document.

Vendors: The Document Foundation.

Quick answers

Is CVE-2026-8357 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-8357 being exploited in the wild.
How severe is CVE-2026-8357?: Informational severity, with a CVSS score of 5.4, published 15 June 2026.
Which products and versions are affected?: The Document Foundation Calc Versions prior to fixed releases (e.g., 24.8.4, 25.2.1, 25.2.2, 25.2.4, 25.8.7, 26.2.3).
Is there a fix for CVE-2026-8357?: 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-2026-8357 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2026-8357?: Check whether you run The Document Foundation Calc at an affected version. 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 buffer overflow exists in LibreOffice Calc's formula compilation engine. The vulnerability is caused by an off-by-one error (CWE-193) in the array used to track formula nesting depth. When a spreadsheet contains a formula with a very large number of opening tokens, the nesting depth exceeds the allocated size of the tracking array, leading to an out-of-bounds write (CWE-787). This is a local attack vector requiring user interaction (opening a file). Successful exploitation could lead to memory corruption, application instability, or potentially arbitrary code execution. The fix involves correctly sizing the array to accommodate the maximum possible nesting depth.

Affected products

The Document Foundation LibreOffice Calc Versions prior to fixed releases (e.g., 24.8.4, 25.2.1, 25.2.2, 25.2.4, 25.8.7, 26.2.3)

Timeline

2026-06-15: disclosed
2026-06-15: advisory

References

https://www.libreoffice.org/about-us/security/advisories/cve-2026-8357

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.