CVE-2019-8266: UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of ClientConnection::Copybuffer function in VNC...

Description

UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of ClientConnection::Copybuffer function in VNC client code, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. User interaction is required to trigger these vulnerabilities. These vulnerabilities have been fixed in revision 1208.

Metrics

EPSS Probability

2.84%

84.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Uvnc	Ultravnc	< 1.2.2.3

References

Timeline

Published: Mar 8, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-8266?

UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of ClientConnection::Copybuffer function in VNC client code, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. User interaction is required to trigger these vulnerabilities. These vulnerabilities have been fixed in revision 1208.

How severe is CVE-2019-8266?

Severity scoring for CVE-2019-8266 is pending analysis. The EPSS model estimates a 2.84% probability of exploitation in the next 30 days.

How do I fix CVE-2019-8266?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.