uvnc UltraVNC up to 1.8.2.2 rfb/dh.cpp vncWc2Mb out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic was found in uvnc UltraVNC up to 1.8.2.2. This affects the function vncWc2Mb of the file rfb/dh.cpp. The manipulation results in out-of-bounds. This vulnerability is reported as CVE-2026-44041. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as problematic has been found in uvnc UltraVNC up to 1.8.2.2. Affected is the function vncWc2Mb of the file rfb/dh.cpp. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. CVE summarizes:

UltraVNC through 1.8.2.2 contains an out-of-bounds read in the wide-string to multibyte conversion helper. In rfb/dh.cpp:204, the vncWc2Mb() function passes a caller-supplied WCHAR pointer to wcslen() before any bounds check. If the caller provides a wide-character buffer that is not properly NUL-terminated, wcslen() reads past the end of the buffer until it encounters a NUL wchar, resulting in an out-of-bounds read. Under typical Win32 API usage this requires an abnormal caller contract. Impact is limited to a potential information disclosure from adjacent memory regions or a process crash (denial of service) if the over-read crosses a page boundary.

The weakness was disclosed by Arjun Basnet. This vulnerability is traded as CVE-2026-44041 since 05/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit.

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

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Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector (securin): 🔒

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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

05/05/2026 CVE reserved
07/01/2026 +57 days Advisory disclosed
07/01/2026 +0 days VulDB entry created
07/01/2026 +0 days VulDB entry last update

Sourcesinfo

Researcher: Arjun Basnet
Status: Not defined

CVE: CVE-2026-44041 (🔒)
GCVE (CVE): GCVE-0-2026-44041
GCVE (VulDB): GCVE-100-375102

Entryinfo

Created: 07/01/2026 07:48
Changes: 07/01/2026 07:48 (64)
Complete: 🔍
Cache ID: 216::103

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