CVE-2026-7831

UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer dn2024 and calls ReadStringdn, 2024. ReadString...

CVE-2026-7838 UltraVNC viewer heap buffer overflow via integer overflow in RFB connection-failure reason length

UltraVNC viewer through 1.8.2.2 contains an integer overflow leading to a heap buffer overflow in the RFB protocol failure-response parsing path. In vncviewer/ClientConnection.cpp, the 4-byte network-supplied reasonLen field type CARD32 is passed as reasonLen+1 to CheckBufferSize. Because both...

EUVD-2026-40884

UltraVNC viewer through 1.8.2.2 contains an integer overflow leading to a heap buffer overflow in the RFB protocol failure-response parsing path. In vncviewer/ClientConnection.cpp, the 4-byte network-supplied reasonLen field type CARD32 is passed as reasonLen+1 to CheckBufferSize. Because both...

CVE-2026-7831

UltraVNC viewer

CVE-2026-7831: Off-by-one Error

UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer dn2024 and calls ReadStringdn, 2024. ReadString...

CVE-2026-7838: Integer Overflow or Wraparound

UltraVNC viewer through 1.8.2.2 contains an integer overflow leading to a heap buffer overflow in the RFB protocol failure-response parsing path. In vncviewer/ClientConnection.cpp, the 4-byte network-supplied reasonLen field type CARD32 is passed as reasonLen+1 to CheckBufferSize. Because both...

CVE-2019-25600

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 t...

CVE-2019-25600

CVE-2019-25600 affects UltraVNC Viewer 1.2.2.4. A denial-of-service exists where an oversized string in the VNC Server input field can cause a buffer overflow and crash the viewer. Attack described: paste a string with 256 repeated characters into the VNC Server field and click Connect. CVSS metr...

UltraVNC Viewer 缓冲区错误漏洞

UltraVNC Viewer is a remote desktop client developed by UltraVNC Corporation. Version 1.2.2.4 of UltraVNC Viewer contains a buffer error vulnerability. This vulnerability stems from a denial-of-service attack on the VNC Server’s input fields, which could allow attackers to cause the application t...

PT-2026-26988

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 t...

CVE-2019-25600: Out-of-bounds Write

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 t...

CVE-2020-37134

UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash...

CVE-2020-37134

UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash...

EUVD-2020-31034

UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash...

CVE-2020-37134: Allocation of Resources Without Limits or Throttling

UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash...

UltraVNC Viewer 安全漏洞

UltraVNC Viewer is a remote desktop client developed by UltraVNC Corporation. Version 1.2.4.0 of UltraVNC Viewer contains a security vulnerability. This vulnerability stems from improper handling of inputs by the VNC server, which may lead to the application crashing...

UltraVNC Viewer 1.2.4.0 - (VNCServer) Denial of Service Exploit

Exploit Title: UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service PoC Discovery by: chuyreds Vendor Homepage: https://www.uvnc.com/ Software Link : https://www.uvnc.com/component/jdownloads/send/0-/394-ultravnc-1240-x86-setup.html?Itemid=0 Tested Version: 1.2.4.0 Vulnerability Type: Local...

UltraVNC Viewer 1.2.2.4 Denial Of Service

Exploit Title: UltraVNC Viewer 1.2.2.4 - Denial of Service PoC Discovery by: Victor Mondragón Discovery Date: 2019-04-14 Vendor Homepage: https://www.uvnc.com/ Software Link: https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html Tested Version: 1.2.2.4 Tested on: Windows 7 x64...

UltraVNC Viewer 1.2.2.4 - VNC Server Denial of Service Exploit

Exploit Title: UltraVNC Viewer 1.2.2.4 - Denial of Service PoC Discovery by: Victor Mondragón Vendor Homepage: https://www.uvnc.com/ Software Link: https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html Tested Version: 1.2.2.4 Tested on: Windows 7 x64 Service Pack 1 Steps to...

UltraVNC Viewer 1.2.2.4 - VNC Server Denial of Service (PoC)

UltraVNC Viewer 1.2.2.4 - VNC Server Denial of Service PoC Exploit Title: UltraVNC Viewer 1.2.2.4 - Denial of Service PoC Discovery by: Victor Mondragón Discovery Date: 2019-04-14 Vendor Homepage: https://www.uvnc.com/ Software Link:...