CVE-2026-45785Public exploit

Process hang via cyclic directory sibling links

Published Jul 17, 2026 · Updated Jul 17, 2026

Infinite loop in OpenMcdf 3.1.3 and earlier allows local users to hang a consuming process via a crafted CFB file. DirectoryTree.TryGetDirectoryEntry follows cyclic Left and Right sibling links during name lookup without detecting revisited entries, so its loop never exits. Exploitation requires a consuming application to open attacker-controlled CFB content and invoke a storage or stream name lookup; the affected thread cannot recover without process termination.

CVSS severity6.2
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite loop in OpenMcdf 3.1.3 and earlier allows local users to hang a consuming process via a crafted CFB file. DirectoryTree.TryGetDirectoryEntry follows cyclic Left and Right sibling links during name lookup without detecting revisited entries, so its loop never exits. Exploitation requires a consuming application to open attacker-controlled CFB content and invoke a storage or stream name lookup; the affected thread cannot recover without process termination.

The record

CVE
CVE-2026-45785
Published
Jul 17, 2026
Updated
Jul 17, 2026
Vendor
OpenMcdf
Product
OpenMcdf
Classifications
CWE-835, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.1.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

OpenMcdf · OpenMcdfversion=< 3.1.4

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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