Vulnerability · Published May 8, 2026 · Assigned by GitHub_M

CVE-2026-41511OpenMcdf has an Infinite loop DoS via crafted CFB directory cycle

Medium 6.2

In plain English

A medium-severity infinite loop in openmcdf from ironfede. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.2Medium

Exploit odds (30 days)0.2%top 91.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
NuGet	openmcdf	3.1.3	GHSA-jxpf-xq2m-q525

Affected products (as reported)

Vendor	Product	Versions
ironfede	openmcdf	< 3.1.3

Weakness: CWE-835 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/openmcdf/openmcdf/security/advisories/GHSA-jxpf-xq2m-q525 x_refsource_CONFIRM
https://github.com/openmcdf/openmcdf/commit/24f445a557fc4f46461cf6d02d296cce16c293a0 x_refsource_MISC
https://github.com/openmcdf/openmcdf/releases/tag/v3.1.3 x_refsource_MISC