CVE-2025-66644: Array Networks ArrayOS AG OS Command Injection Vulnerability

In short

Array Networks ArrayOS AG has a weakness classified as OS command injection (CWE-78). CISA added it to its Known Exploited Vulnerabilities catalog on 2025-12-08. NVD lists CVSS 3.1 at 9.8 CRITICAL.

What it is

“Array Networks ArrayOS AG contains an OS command injection vulnerability that could allow an attacker to execute arbitrary commands.” — CISA KEV, retrieved 2026-11-01

“Array Networks ArrayOS AG before 9.4.5.9 allows command injection, as exploited in the wild in August through December 2025.” — NVD, retrieved 2026-11-01

Who is affected

Array Networks ArrayOS AG. NVD lists the following versions as affected:

• Versions before 9.4.5.9

Exploitation status

CISA KEV added: 2025-12-08. Known ransomware campaign use: Not reported by CISA. Due date CISA set for US federal civilian agencies: 2025-12-29.

Scores

NVD CVSS 3.1: 9.8 CRITICAL; vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source [email protected].

EPSS by FIRST: 3.42%; percentile 88.89; score date 2026-10-31. EPSS estimates the probability of exploitation in the next 30 days.

CWE: CWE-78.

Timeline

CISA required action

“Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.” — CISA KEV

What to do

• Confirm whether you run Array Networks ArrayOS AG and which version.
• Apply the vendor update or mitigation in the vendor advisory.
• Follow CISA’s required action.
• Review the vendor guidance on signs of compromise.
• Track the fix through completion.

References

• Third Party Advisory: https://www.jpcert.or.jp/at/2025/at250024.html
• Third Party Advisory: https://x.com/ArraySupport/status/1921373397533032590
• NVD detail
• CVE.org record
• CISA KEV catalog

Sources and dates

CISA Known Exploited Vulnerabilities Catalog, version 2026.10.30; retrieved 2026-11-01. CISA KEV data: CC0 1.0. No endorsement by CISA.

NVD retrieved: 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

EPSS scores by FIRST; score date 2026-10-31.