CVE-2026-41511
Medium
Description
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.
SeverityMedium
CVSS6.2
Exploit probability—
ProductOpenmcdf
PublishedMay 8, 2026
First seenMay 8, 2026
Weakness typeCWE-835CWE-835
How to fix
Update
- openmcdf openmcdf3.1.3 or later
- OpenMcdf3.1.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| openmcdf openmcdf | v < 3.1.3 | 3.1.3 |
| OpenMcdfNuGet | v < 3.1.3 | 3.1.3 |
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