Technology · UltraVNC
UltraVNC vulnerabilities
Updated . Rebuilt every hour.
Junglewise Threat Intelligence has tracked 4 vulnerabilities in UltraVNC: 0 in the last 7 days and 4 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-7838, was published on 1 July 2026.
- Last 7 days
- 0
- Last 90 days
- 4
- Critical, all time
- 0
- Exploited in the wild
- 0
About UltraVNC
UltraVNC is a powerful, easy to use and free software that can display the screen of another computer (via internet or network) on your own screen.
Latest UltraVNC vulnerabilities
- CVE-2026-7838: UltraVNC viewer heap buffer overflow in RFB failure-response parsinghighCVSS 8.8
- CVE-2026-7830: UltraVNC weak cryptography in MS-Logon II authenticationhighCVSS 7.4
- CVE-2026-44041: UltraVNC out-of-bounds read in vncWc2Mb conversion helpermediumCVSS 4.3
- CVE-2026-44040: UltraVNC weak PRNG in VNC authentication challengemediumCVSS 4.8
Most severe UltraVNC vulnerabilities
Exploited in the wild first, then by severity and CVSS score.
- CVE-2026-7838: UltraVNC viewer heap buffer overflow in RFB failure-response parsinghighCVSS 8.8
- CVE-2026-7830: UltraVNC weak cryptography in MS-Logon II authenticationhighCVSS 7.4
- CVE-2026-44040: UltraVNC weak PRNG in VNC authentication challengemediumCVSS 4.8
- CVE-2026-44041: UltraVNC out-of-bounds read in vncWc2Mb conversion helpermediumCVSS 4.3
Vulnerabilities per week
The last 13 weeks, by the week each vulnerability was published.
| Week of | Bar | Vulns | Critical |
|---|---|---|---|
| 29 Jun 2026 | 4 | 0 | |
| 6 Jul 2026 | 0 | 0 | |
| 13 Jul 2026 | 0 | 0 | |
| 20 Jul 2026 | 0 | 0 | |
| 27 Jul 2026 | 0 | 0 | |
| 3 Aug 2026 | 0 | 0 | |
| 10 Aug 2026 | 0 | 0 | |
| 17 Aug 2026 | 0 | 0 | |
| 24 Aug 2026 | 0 | 0 | |
| 31 Aug 2026 | 0 | 0 | |
| 7 Sep 2026 | 0 | 0 | |
| 14 Sep 2026 | 0 | 0 | |
| 21 Sep 2026 | 0 | 0 |
How this is built
Junglewise Threat Intelligence collects vulnerabilities from NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories, and matches each one to the technologies and vendors it affects. Dates are the date a vulnerability was published, in UTC.
The pages are rebuilt from the database every hour. Frozen weekly and monthly reports never change once published, so they can be cited.
Use this data
The same data is at https://junglewise.ai/threats/technologies/ultravnc.json, for scripts and language models. It is free to reuse under CC BY 4.0 with a link back to this page.
Cite as: Junglewise Threat Intelligence, "UltraVNC vulnerabilities", https://junglewise.ai/threats/technologies/ultravnc, 26 September 2026.