https://db.gcve.eu/rss/recent/all/10 Most recent entries from all 2026-10-03T11:51:47.490206+00:00 Vulnerability-Lookup info@gcve.eu python-feedgen Contains only the most 10 recent entries. https://db.gcve.eu/vuln/fkie_cve-2026-45785 fkie_cve-2026-45785 2026-10-03T11:51:47.507337+00:00

OpenMcdf is a fully .NET / C# library to manipulate Compound File Binary File Format files, also known as Structured Storage. In 3.1.3 and earlier, the BST name-lookup loop in DirectoryTree.TryGetDirectoryEntry (OpenMcdf/DirectoryTree.cs:35-46) walks directory entries by repeatedly calling directories.TryGetSibling(child, siblingType, validateColor). A crafted CFB file with cyclic Left/Right sibling links among directory entries, constructed so the per-step BST-order check in TryGetSibling (DirectoryEntries.cs:84-85) is satisfied at every step, drives this while (child is not null) loop forever. There is no cycle detection in TryGetDirectoryEntry, and the bug is reachable from RootStorage.OpenStorage(name), TryOpenStorage(name), OpenStream(name), and TryOpenStream(name), causing an unrecoverable denial of service. This issue is fixed in version 3.1.4.

 https://db.gcve.eu/vuln/ghsa-5qwm-7pvp-w988 GHSA-5qwm-7pvp-w988 — OpenMcdf: Uncatchable infinite loop in DirectoryTree.TryGetDirectoryEntry on crafted CFB directory cycle 2026-10-03T11:51:47.507410+00:00

Affected: NuGet: OpenMcdf

### Summary The BST name-lookup loop in `DirectoryTree.TryGetDirectoryEntry` (`OpenMcdf/DirectoryTree.cs:35-46`) walks directory entries by repeatedly calling `directories.TryGetSibling(child, siblingType, validateColor)`. A crafted CFB file with cyclic Left/Right sibling links among directory entries - constructed so the per-step BST-order check in `TryGetSibling` (`DirectoryEntries.cs:84-85`) is satisfied at every step - drives this `while (child is not null)` loop forever. There is no cycle detection in `TryGetDirectoryEntry`.

### Details The recent Brent's-algorithm commit ([`24f445a`](https://github.com/openmcdf/openmcdf/commit/24f445a557fc4f46461cf6d02d296cce16c293a0)) protects `DirectoryTreeEnumerator` and works correctly for both attached repros - pure `EnumerateEntries()` throws `FileFormatException: Directory tree contains a loop` cleanly. The unprotected code path is the lookup-by-name loop, which is reached from multiple public APIs: - `RootStorage.OpenStorage(name)` / `TryOpenStorage(name)` - `RootStorage.OpenStream(name)` / `TryOpenStream(name)`

The second one matters most: typical consumers iterate `EnumerateEntries()` and call `OpenStream(entry.Name)` per Stream entry. With Brent's algorithm catching the enumeration cycle but not the per-entry lookup, callers can still hang as soon as they touch a streamed entry.

### PoC Two minimal repros attached, demonstrating the same lookup-loop bug reached via two different public APIs:

- `repro_lookup.cfb` (5,632 b…