CVE-2026-45785

Description

OpenMcdf: Uncatchable infinite loop in DirectoryTree.TryGetDirectoryEntry on crafted CFB directory cycle

Overview

State

—

Assigner (CNA)

—

CVSS severity

medium

CVSS score

6.2 / 10

CVSS vector

AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Effective score

6.2 / 10 MEDIUM source: CNA overview

CWE(s)

—

Reserved

—

Published

—

Last updated

—

Source

https://www.tenable.com/cve/CVE-2026-45785

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2026-45326

Assigner

GitHub_M

Published

Jul 17, 2026, 8:37:23 PM

Updated

Jul 21, 2026, 2:20:18 AM

EUVD base score (CVSS 3.1)

6.2 / 10
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EUVD-reported EPSS

0.1300

Vendors

openmcdf

Products

openmcdf (< 3.1.4)

Aliases

GHSA-5qwm-7pvp-w988

ENISA description: 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.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

Web references (2)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://nvd.nist.gov/vuln/detail/CVE-2026-45785 tenable:nvd.nist.gov
• https://www.cve.org/CVERecord?id=CVE-2026-45785 tenable:www.cve.org

• CISA Warns of Exploited Microsoft Defender 0-Day Flaws
  web:cyberpress.org

  The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

  2026-05-26 03:08 UTC
• Microsoft Releases Mitigation for Windows BitLocker Security Bypass 0 ...
  web:cybersecuritynews.com

  No patch has been released yet; Microsoft has instead issued a multi-step manual mitigation guide while a formal security update is prepared. Windows BitLocker Security Bypass The vulnerability originates in WinRE's handling of the BootExecute registry value under HKLM\ControlSet001\Control\Session Manager.

  2026-05-26 03:08 UTC
• Security Update Guide - Microsoft
  web:portal.msrc.microsoft.com

  The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

  2026-05-26 03:08 UTC
• MC1318295: Mitigation guidance updated with a new script for ... - PUPUWEB
  web:pupuweb.com

  Microsoft has updated the mitigation guidance in CVE - 2026 -45585, a Windows BitLocker security feature bypass vulnerability. The updated guidance replaces previously documented manual mitigation steps with a script that helps reduce exposure while a future security update is developed to address this vulnerability.

  2026-05-26 03:08 UTC
• ArcGIS Server Security 2025 Update 2 Patch - Esri Support
  web:support.esri.com

  This security patch addresses multiple security vulnerabilities found in ArcGIS Server. Esri recommends that all customers using ArcGIS Server 11.5, 11.4, 11.3, 11.1 and 10.9.1 apply this patch .

  2026-05-26 03:08 UTC
• Microsoft provides mitigation for "YellowKey" BitLocker bypass flaw ...
  web:www.helpnetsecurity.com

  Microsoft is working on a fix for CVE - 2026 -45585 (aka "Yellowkey"), a vulnerability that can be used to bypass Windows' BitLocker protection.

  2026-05-26 03:08 UTC
• Microsoft mitigates YellowKey BitLocker bypass, no patch yet
  web:www.notebookcheck.net

  Microsoft released mitigation steps for YellowKey ( CVE - 2026 -45585), a BitLocker bypass that grants physical attackers access to encrypted Windows drives.

  2026-05-26 03:08 UTC
• Oracle Critical Patch Update Advisory - April 2026
  web:www.oracle.com

  This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

  2026-05-26 03:08 UTC
• Microsoft Rolls Out Mitigations for 'YellowKey' BitLocker ...
  web:www.securityweek.com

  Microsoft has announced mitigations for CVE - 2026 -45585, a BitLocker bypass triggered via FsTx in Windows Recovery.

  2026-05-26 03:08 UTC
• Patch Tuesday May 2026: Security Updates & CVE Analysis
  web:zecurit.com

  Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

  2026-05-26 03:08 UTC

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