Cisco Unified CM Flaw CVE-2026-20230 Now Exploited

First reported on bleepingcomputer on June 24, 2026.

A security flaw in Cisco's Unified Communications Manager Server is being exploited in attacks, which could allow hackers to access sensitive information.

What it looks like

  • Cisco Unified CM not responding to requests
  • Cisco Unified CM not syncing with other systems

How to fix it

  1. Contact Cisco support for assistance with patching the vulnerability.
  2. Ensure all systems are properly configured and up-to-date.
  3. Monitor your network for any suspicious activity.
  4. Change passwords for all affected accounts.
  5. If issues persist, consider seeking professional help.

Affected products

  • Cisco Unified CM

Sources

Search terms covered: Cisco Unified CM not responding to requests, Cisco Unified CM not syncing with other systems