Cisco security incident history
Hacking, data breaches and other security incidents involving Cisco, with related coverage.
Cisco Salesforce CRM breach puts 3 million customer records at risk
3mImpact: 3 million customer records at risk of exposure
A breach occurred in Cisco's Salesforce customer relationship management system. The incident put 3 million customer records at risk, and whether data was actually leaked and the response have not been confirmed.
Related reports: 3 · last report →Cisco hit by voice phishing, website user data stolen
Impact: Profile information of users registered on Cisco.com
Cisco was hit by a voice phishing attack, and user information was stolen from its customer relationship management system. The leaked data included profile information of users registered on Cisco.com. Cisco disclosed the data breach affecting user accounts.
Related reports: 5 · last report →Cisco cloud data stolen and published online
Impact: 2.9GB of data published online; attackers claim 4.5TB stolen in total
Allegations of a Cisco data breach surfaced in October 2024, and in December IntelBroker published online 2.9GB of Cisco-related data stolen from a cloud instance. The attackers claimed the total amount stolen was 4.5TB. Cisco said the additional leak in December and material published by a ransomware gang in February 2025 were linked to the earlier hack.
Related reports: 9 · last report →Breach at Cisco Duo authentication provider leaks SMS authentication logs
Impact: Authentication message logs of some customers, including phone numbers, carriers, locations and times
Cisco Duo's North American telephony and SMS authentication provider was breached through an employee account compromised by phishing. The attacker downloaded authentication message logs containing some customers' phone numbers, carriers, locations and times. The provider said message contents were not accessed, and Cisco Duo disclosed the leak.
Related reports: 2 →