CVE-2026-3787 json
UltraVNC Windows Service cryptbase.dll uncontrolled search path
published 2026-03-08 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-10277
- cvss
- 7.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 8%
- public exploits
- 0
- none known
Summary
A weakness has been identified in UltraVNC 1.6.4.0 on Windows. This affects an unknown function in the library cryptbase.dll of the component Windows Service. This manipulation causes uncontrolled search path. The attack requires local access. A high degree of complexity is needed for the attack. The exploitability is reported as difficult. The vendor was contacted early about this disclosure but did not respond in any way.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 7 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.3 | CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P |
| CNA | 3.1 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R |
| CNA | 3.0 | 7.0 | CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R |
| CNA | 2.0 | 6.0 | AV:L/AC:H/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR |
| CNA | 4.0 | 6.4 | CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| CNA | 3.1 | 7.0 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 2.0 | 6.0 | AV:L/AC:H/Au:S/C:C/I:C/A:C |
Affected products
- n/a UltraVNC
Classification
References
-
vuldb.com
/?id.349754
vdb-entry, third-party-advisory
-
vuldb.com
/?ctiid.349754
signature, permissions-required, vdb-entry
-
vuldb.com
/?submit.767257
third-party-advisory, vdb-entry
-
drive.google.com
/file/d/14ixv_1i4D2VrZWyl4RKsvFcN1AMF_qNx/view
related, permissions-required
Sources
- CVE List CVE-2026-3787
- NVD CVE-2026-3787
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.