CVE-2026-41511: Openmcdf

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

OpenMcdf is a fully .NET / C# library to manipulate Compound File Binary File Format files, also known as Structured Storage. Prior to version 3.1.3, OpenMcdf does not detect cycles in the directory entry red-black tree of a Compound File Binary (CFB) document. A crafted CFB file with a cycle in the LeftSiblingID / RightSiblingID chain causes Storage.EnumerateEntries() and Storage.OpenStream() to loop indefinitely, consuming the calling thread with no possibility of recovery via try/catch. This issue has been patched in version 3.1.3.

Affected products

• Openmcdf Openmcdf: before 3.1.3 (fixed in 3.1.3)

Published 2026-05-08. Last modified 2026-06-17.