CRITICALZero Day
Verified
Global

Ivanti Connect Secure New Zero-Day Under Active Exploitation

·Source: Mandiant / Ivanti

Updated:

Executive Summary

Another zero-day in Ivanti Connect Secure VPN appliances. Stack buffer overflow enables unauthenticated RCE. Third major Ivanti VPN zero-day in two years.

Analysis

CVE-2026-18321 is a stack buffer overflow in Ivanti Connect Secure allowing unauthenticated RCE via crafted IKEv2 packets. Mandiant has observed exploitation by suspected Chinese state-sponsored actors. This is the third major zero-day in Ivanti VPN products since January 2024. Ivanti released emergency patches and recommends factory reset before patching.

Timeline

Discovered
Mar 8, 2026
Exploitation Detected
Mar 8, 2026
Published
Mar 15, 2026
Patch Available
Mar 15, 2026

Indicators of Compromise (1)

CVE (1)
CVE-2026-18321
NVDMITRE CVE
Source Attribution

Originally published by Mandiant / Ivanti on Mar 15, 2026. Verified by: CISA, Mandiant, Ivanti.

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