CVE-2026-3664: Xlnt-Community Xlnt

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability was determined in xlnt-community xlnt up to 1.6.1. Impacted is the function xlnt::detail::compound_document::read_directory of the file source/detail/cryptography/compound_document.cpp of the component Encrypted XLSX File Parser. Executing a manipulation can lead to out-of-bounds read. The attack is restricted to local execution. The exploit has been publicly disclosed and may be utilized. This patch is called 147. Applying a patch is advised to resolve this issue.

Affected products

• Xlnt-Community Xlnt: up to and including 1.6.1

Published 2026-03-07. Last modified 2026-06-17.