CVEs / CVE-2026-110447
CVE-2026-110447: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability
- Known exploited in the CISA KEV catalog since 23 Oct 2026
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 73.3% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
Description
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Collabora Collabora Online - Built-in CODE Server | before 26.4.303 | 26.4.303 |
Exploitation
| In CISA KEV since | 23 Oct 2026 |
|---|---|
| Due date for US federal agencies | 26 Oct 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-78 |
On the Stackurity blog
References
- CVE-2026-110447 on NVD
- CVE-2026-110447 in the CISA KEV catalog
- https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 (cited by CISA)
- https://github.com/CollaboraOnline/online/security/advisories/GHSA-g3vx-3m76-fghh (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- CVE-2026-110447 on OSV
- https://github.com/CollaboraOnline/richdocumentscode/issues/354 Issue Tracking
- https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.