CISA warns admins to immediately fix Ivanti flaw exploited as zero-day
CISA says patch Ivanti Connect Secure CVE-2026-104935, exploited as a zero-day for unauthenticated command execution.
Unauthenticated Stack Buffer Overflow RCE in Ivanti Connect Secure
CISA: Ivanti Connect Secure, Policy Secure, and ZTA Gateways Stack-Based Buffer Overflow Vulnerability
Ivanti Connect Secure, Policy Secure, and ZTA Gateways contain a stack-based buffer overflow (CWE-121) that can be triggered by a remote, unauthenticated attacker sending crafted input that overruns a fixed-size stack buffer on the affected gateway. Successful exploitation yields remote code execution on the appliance, giving an attacker control of an enterprise VPN or zero-trust access gateway and a foothold in the surrounding network. Any organization running the affected Ivanti gateway products is exposed, with impact concentrated among enterprises using these appliances for remote-access VPN and zero-trust network access. The vulnerability was added to CISA's KEV catalog on 2025-04-04 with known ransomware use, and its maximum EPSS score (100.0%, 100th percentile) signals near-certain exploitation pressure within 30 days. No public proof-of-concept is known, but confirmed in-the-wild exploitation makes this an actively abused, high-priority flaw.
What to do: Apply the mitigations required by CISA and update Connect Secure, Policy Secure, and ZTA Gateways to the patched releases designated in Ivanti's advisory, prioritizing internet-exposed VPN gateways. Given known ransomware use, review appliance and downstream logs for signs of compromise, and treat unpatched gateways as high risk given the 100th-percentile EPSS score.
| Product | Affected |
|---|---|
| Ivanti Connect Secure | — |
| Ivanti Policy Secure | — |
| Ivanti ZTA Gateways | — |
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
A stack-based buffer overflow in Ivanti Connect Secure before version 22.7R2.6, Ivanti Policy Secure before version 22.7R1.4, and Ivanti ZTA Gateways before version 22.8R2.2 allows a remote unauthenticated attacker to achieve remote code execution.
CISA says patch Ivanti Connect Secure CVE-2026-104935, exploited as a zero-day for unauthenticated command execution.
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