Four of the advisories deal with critical vulnerabilities which can be remotely exploited, one which is due to a hard-coded password in a device.
One of the critical flaws had been advertised on 5 February but the company said it had now discovered additional attack vectors.
It pertains to a vulnerability in the XML parser of Cisco Adaptive Security Appliance software that could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code.
The other two critical vulnerabilities also concerned the Cisco Digital Network Architecture Center. In one case, a vulnerability in the API gateway could allow an unauthenticated, remote attacker to bypass authentication and access critical services.
And in the last of the critical flaws, a vulnerability in the container management subsystem could allow an unauthenticated, remote attacker to bypass authentication and gain elevated privileges.
Details of the vulnerabilities are here and Cisco's patches are linked off the respective pages.