CVE-2026-3787
Received Received - Intake

Uncontrolled Search Path in UltraVNC cryptbase.dll on Windows

Publication date: 2026-03-08

Last updated on: 2026-04-29

Assigner: VulDB

Description
A weakness has been identified in UltraVNC 1.6.4.0 on Windows. This affects an unknown function in the library cryptbase.dll of the component Windows Service. This manipulation causes uncontrolled search path. The attack requires local access. A high degree of complexity is needed for the attack. The exploitability is reported as difficult. The vendor was contacted early about this disclosure but did not respond in any way.

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Meta Information

Published
2026-03-08
Last Modified
2026-04-29
Generated
2026-07-06
AI Q&A
2026-03-09
EPSS Evaluated
2026-07-04
NVD
CVE-2026-3787
EUVD
EUVD-2026-10277

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
uvnc ultravnc 1.6.4.0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-426 The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.
CWE-427 The product uses a fixed or controlled search path to find resources, but one or more locations in that path can be under the control of unintended actors.

Attack-Flow Graph

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Impact Analysis

If exploited, this vulnerability can lead to a compromise of confidentiality, integrity, and availability of the affected system. Because it involves uncontrolled search path manipulation, an attacker with local access might execute malicious code or cause the system to behave unexpectedly, potentially leading to significant security breaches.

Compliance Impact

I don't know

Detection Guidance

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Mitigation Strategies

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Executive Summary

This vulnerability exists in UltraVNC version 1.6.4.0 on Windows, specifically involving an unknown function in the cryptbase.dll library of the Windows Service component. It causes an uncontrolled search path, which means the system may load malicious files from unintended locations. Exploiting this vulnerability requires local access to the system and is considered difficult due to the high complexity involved.

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