PT-2026-6578 · Realvnc · Ultravnc Viewer

Chuyreds · Published 2026-02-05 · Updated 2026-02-05 · CVE-2020-37134

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions UltraVNC Viewer version 1.2.4.0

Description The software contains a denial of service issue that allows attackers to crash the application. Attackers can create a 256-byte malformed payload and paste it into the VNC Server connection dialog, which triggers an application crash.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

DoS

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2020-37134

Affected Products

Ultravnc Viewer

References · 5

• 🔥 https://exploit-db.com/exploits/48291 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2020-37134 · Security Note
• https://t.me/CVEtracker/43826 · Telegram Post
• https://vulncheck.com/advisories/ultravnc-viewer-vncserver-denial-of-service · Note
• https://uvnc.com · Note