China-Linked Hackers Exploiting Zero-Day in Cisco Security Gear

SecurityWeek

December 18, 2025 at 7:12 AM

Actively Exploited

CVE Zero-day Cisco Exploit Vulnerability Critical

Overview

A new vulnerability, tracked as CVE-2025-20393, has been discovered in Cisco's Secure Email Gateway and Secure Email and Web Manager appliances. This zero-day flaw is reportedly being exploited by hackers linked to China, posing a significant risk to organizations using these products. The vulnerability allows attackers to bypass security controls, potentially leading to unauthorized access and data breaches. Companies using these Cisco appliances should prioritize patching and monitoring their systems to mitigate the risks associated with this exploit. The discovery of this flaw is particularly concerning given the ongoing cyber threats targeting critical infrastructure and enterprise environments.

Key Takeaways

Active Exploitation: This vulnerability is being actively exploited by attackers. Immediate action is recommended.
Affected Systems: Cisco Secure Email Gateway, Cisco Secure Email and Web Manager appliances
Action Required: Organizations should apply any available patches from Cisco for the affected appliances.
Timeline: Newly disclosed

Original Article Summary

The critical zero-day is tracked as CVE-2025-20393 and it impacts Secure Email Gateway and Secure Email and Web Manager appliances. The post China-Linked Hackers Exploiting Zero-Day in Cisco Security Gear appeared first on SecurityWeek.

Impact

Cisco Secure Email Gateway, Cisco Secure Email and Web Manager appliances

Exploitation Status

This vulnerability is confirmed to be actively exploited by attackers in real-world attacks. Organizations should prioritize patching or implementing workarounds immediately.

Timeline

Newly disclosed

Remediation

Organizations should apply any available patches from Cisco for the affected appliances. Additionally, they should enhance monitoring and security measures around their email systems to detect any suspicious activity.

Additional Information

This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.

Related Topics: This incident relates to CVE, Zero-day, Cisco, and 3 more.

Read Original Article

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