UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.

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History

Tue, 24 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 23 Mar 2026 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Uvnc
Uvnc ultravnc Viewer
Vendors & Products Uvnc
Uvnc ultravnc Viewer

Sun, 22 Mar 2026 13:45:00 +0000

Type Values Removed Values Added
Description UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.
Title UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow
Weaknesses CWE-787
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-03-24T15:14:43.698Z

Reserved: 2026-03-22T12:59:37.342Z

Link: CVE-2019-25600

cve-icon Vulnrichment

Updated: 2026-03-24T14:09:30.439Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-22T14:16:27.343

Modified: 2026-03-23T14:31:37.267

Link: CVE-2019-25600

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-23T09:46:19Z

Weaknesses