CVE-2026-104935: Ivanti Connect Secure Authentication Bypass by Spoofing Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Ivanti Connect Secure. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-10-13, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-10-16; treat that as the outer limit, not the target.
• EPSS 26.0%, percentile 98: FIRST’s model estimates a 26.0% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Editorial verdict: Act now. Ivanti Connect Secure CVE-2026-104935: Exploited Zero-Day — Upgrade Connect Secure today and investigate with memory and network forensics, because the Integrity Checker missed this compromise and part of the attack chain still has no fix.

What it is

Authentication bypass by spoofing in ICS before version 25.1.3.0 allows a remote unauthenticated attacker to execute arbitrary commands. This does not impact ICS version 22.7R2.14 or prior.

CISA’s summary

Ivanti Connect Secure contains an authentication bypass by spoofing vulnerability that allows a remote unauthenticated attacker to execute arbitrary commands.

Weakness type: CWE-290.

Product: Ivanti Connect Secure · Assigned by: ivanti · Published: 2026-10-13

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-10-13; federal due date 2026-10-16. Known ransomware use: Unknown.
• CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 25.98% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2026-10-13 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-10-13 — CVE record last updated
• 2026-10-13 — CVE record published by ivanti
• 2026-10-13 — erroneo.us brief: Ivanti Connect Secure CVE-2026-104935: Exploited Zero-Day
• 2026-10-16 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. CVE.org record CVE-2026-104935 cve.org
2. NVD entry CVE-2026-104935 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

1. hub.ivanti.com hub.ivanti.com

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