Overview

On October 13, 2026, Ivanti published a security advisory for CVE-2026-104935, a high-severity authentication bypass by spoofing (CWE-290) affecting Ivanti Connect Secure (ICS). The vulnerability has a CVSSv3.0 score of 8.6 and allows a remote, unauthenticated attacker to execute arbitrary commands.

Ivanti reports that exploitation in the wild has already occurred prior to disclosure, affecting a limited number of customers. This indicates that exploitation has been occurring as a zero-day vulnerability. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) confirms exploitation in the wild, and added CVE-2026-104935 to its Known Exploited Vulnerabilities (KEV) catalog on the same day as the vendor's public disclosure. The digital forensics firm Volexity has published a detailed blog post describing the threat actor activity, which was detected in early October 2026. Volexity notes that in addition to leveraging CVE-2026-104935 as a zero-day, the threat actor also leveraged an as-yet unpatched privilege escalation vulnerability which Ivanti are planning to patch at a later date.

According to the vendor, a portion of the vulnerability was initially discovered through its product security program and patched in the July 2026 release of 25.1.3.0. Exploitation occurred while Ivanti was working to backport the fix to the remaining supported versions.

Ivanti Connect Secure is a popular enterprise VPN solution and naturally sits on the edge of a corporate environment. The product has a history of being targeted by attackers, with zero-day exploitation of other vulnerabilities occurring back in both 2024 and 2025.

Given the confirmed exploitation, the ability to execute commands without authentication, along with the history of the product, Rapid7 recommends that organizations running affected versions apply the appropriate update on an emergency basis outside of normal patching cycles.

Mitigation guidance

Vendor-supplied updates are available to remediate CVE-2026-104935. Ivanti lists the following affected and resolved versions:

Ivanti Connect Secure affected versions

Resolved versions

25.1.1.1 and prior in the applicable code line

25.1.1.2

25.1.2.2 and prior in the applicable code line

25.1.3.0, 25.1.3.1

22.8R2.4 and prior in the applicable code line

22.8R2.5

Note that the vendor advisory confirms that versions 22.7.x and below are unaffected.

At the time of the advisory, Ivanti states that reliable indicators of compromise are not available, however Volexity have published several here. Rapid7 strongly recommends looking for signs of compromise even after the patch has been applied. Customers who suspect exploitation should follow the vendor's recovery steps.

For the latest mitigation guidance, please refer to the vendor's security advisory.

Rapid7 customers

Exposure Command, Vulnerability Management, and Nexpose

Exposure Command, Vulnerability Management, and Nexpose customers can assess exposure to CVE-2026-104935 with a vulnerability check expected to be available in the October 14 content release.