CVE-2015-4195: Cisco IOS XR 5.1.1.K9SEC allows remote authenticated users to cause a denial of service (vty error, and SSH...

Security readout for executives and security teams

This issue can let a logged-in remote user disrupt management access on affected Cisco IOS XR systems. The reported effect is a vty error and outage of SSH and Telnet services, which could impede administration during operations or incidents. Exposure appears limited to Cisco IOS XR 5.1.1.K9SEC systems with remote administrative access enabled. The provided affected-product metadata is incomplete, so confirm exact versions against Cisco guidance. Prioritize for network infrastructure where management access availability is critical. The main business risk is loss of administrative access, especially during incidents, not confirmed data theft or device takeover. Mitigation focus: Review Cisco advisory 39402 and Bug ID CSCul63127 for fixed releases or workarounds.; Restrict IOS XR management access to trusted administrative networks and accounts.; Disable Telnet where operationally possible and prefer controlled SSH management paths..

Prepared

Jun 13, 2026, 22:39 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.