CVE-2026-4430

Description

Out-of-bounds write vulnerability in The Document Foundation LibreOffice via crafted OOXML documents with mismatched encryption salt parameters. This issue affects LibreOffice: from 26.2 before 26.2.3, from 25.8 before 25.8.7.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
libreoffice	libreoffice	25.8.0.0 — 25.8.7.0
libreoffice	libreoffice	26.2.0.0 — 26.2.3.0

References

Advisories & Patches

https://www.libreoffice.org/about-us/security/advisories/cve-2026-4430

Frequently Asked Questions

What is CVE-2026-4430? +

Out-of-bounds write vulnerability in The Document Foundation LibreOffice via crafted OOXML documents with mismatched encryption salt parameters. This issue affects LibreOffice: from 26.2 before 26.2.3, from 25.8 before 25.8.7. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-4430? +

CVE-2026-4430 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-4430? +

CVE-2026-4430 affects products from libreoffice, specifically: libreoffice. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-4430? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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