Cisco updates warning on critical SD-WAN Manager flaw

Cisco is urging administrators of affected Catalyst SD-WAN Manager systems to install fixed software after reporting active exploitation of a critical authentication flaw. Its advisory was updated Oct. 2.

The vulnerability, CVE-2026-76504, can allow an unauthenticated attacker to gain administrative access. Cisco says it became aware of exploitation in September.

A newly released Live Protect shield provides temporary, partial protection. Cisco says upgrading to an appropriate fixed release is the remedy; administrators should use the current advisory to match their software version to the required update.

The advisory says Cisco SD-WAN Cloud (Cisco Managed) release 20.15.605 addresses the flaw without requiring customer action. Cisco maintains an office in Richardson.

Cisco’s current security advisory. Cisco’s office directory.