UltraVNC 1.6.4.0 on Windows Windows Service cryptbase.dll uncontrolled search path

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.7$0-$5k0.22

Summaryinfo

A vulnerability was found in UltraVNC 1.6.4.0 on Windows. It has been declared as problematic. This impacts an unknown function in the library cryptbase.dll of the component Windows Service. Such manipulation leads to uncontrolled search path. This vulnerability is traded as CVE-2026-3787. An attack has to be approached locally. Furthermore, there is an exploit available. The vendor was contacted early about this disclosure but did not respond in any way.

Detailsinfo

A vulnerability was found in UltraVNC 1.6.4.0 on Windows and classified as critical. Affected by this issue is some unknown processing in the library cryptbase.dll of the component Windows Service. The manipulation with an unknown input leads to a uncontrolled search path vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability.

The advisory is available at drive.google.com. This vulnerability is handled as CVE-2026-3787. The exploitation is known to be difficult. Local access is required to approach this attack. Technical details as well as a exploit are known. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 03/12/2026). This vulnerability is assigned to T1574 by the MITRE ATT&CK project.

It is declared as proof-of-concept. The vendor was contacted early about this disclosure but did not respond in any way.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-10277). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.7

VulDB Base Score: 7.0
VulDB Temp Score: 6.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.0
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uncontrolled search path
CWE: CWE-427 / CWE-426
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Proof-of-Concept

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/08/2026 Advisory disclosed
03/08/2026 +0 days VulDB entry created
03/12/2026 +4 days VulDB entry last update

Sourcesinfo

Advisory: drive.google.com
Status: Not defined

CVE: CVE-2026-3787 (🔒)
GCVE (CVE): GCVE-0-2026-3787
GCVE (VulDB): GCVE-100-349754
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 03/08/2026 08:16
Updated: 03/12/2026 16:36
Changes: 03/08/2026 08:16 (55), 03/09/2026 01:14 (30), 03/09/2026 02:08 (1), 03/12/2026 16:36 (1)
Complete: 🔍
Submitter: haehanse
Cache ID: 216:B7C:103

Submitinfo

Accepted

  • Submit #767257: UltraVNC 1.6.4.0 Uncontrolled Search Path (by haehanse)

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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