CVE-2019-25600CWE-787

UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow

High · published March 22, 2026

CVSS v4.0
7.1
EPSS
1%
Percentile
52.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.1 · HIGH
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
EPSS
0.00701 · 52.7th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-03-22T13:38Z
EPSS history
Timeline
  • 22 MAR 13:38Z
    UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow
    cvelistv5