OS command injection
Input changes a command that the server runs through its operating system.
CWE-78 · CISA KEV; NVD record: cve@mitre.org
Reading and practice labs · Free account for labs. Basic HTTP knowledge; some labs use Burp Suite.
Exploited. On CISA's list since 2026-10-23.
Collabora Online – Built-in CODE Server OS Command Injection Vulnerability
CVE-2026-110447 · Collabora Collabora Online – Built-in CODE Server · Published 2026-10-14
How bad would it be?
9.2 out of 10
CVSS rates it critical: about as damaging as flaws get.
How likely is it to be used?
73%
Estimated chance of exploitation in the next 30 days, among the top 1% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 4 days ago (2026-10-26).
What CISA says to do
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.
Collabora Collabora Online – Built-in CODE Server when used within the NextCloud platform contains an OS command injection vulnerability that allows for remote code execution when the CODE server isn't running.
What the flaw is
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.
From the NVD.
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On SentryFeed
Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.