CVE-2026-110447
critical CISA KEVCollabora Online – Built-in CODE Server OS Command Injection Vulnerability
Vendor / product: Collabora — Collabora Online – Built-in CODE Server
Collabora Online Built-in CODE Server before 26.4.303 (richdocumentscode), a Nextcloud app, allows remote code execution, as exploited in the wild in September and October 2026, a different vulnerability than CVE-2025-66208. This is an OS command injection in proxy.php when the CODE server isn't running (e.g., the product was recently restarted). The vulnerability is not present in standalone Collabora Online servers; only this deployment with CODE Server is affected.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Required action (CISA)
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.
Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/CollaboraOnline/richdocumentscode/issues/354 cve@mitre.org
- https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 cve@mitre.org
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447 134c704f-9b21-4f2e-91b3-4a467353bcc0