CVE-2026-110447
Collabora Online – Built-in CODE Server OS Command Injection Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 26 October 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 4.0
- 9.2 CRITICALCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 12.33% probability · 96th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 23 October 2026 · due 26 October 2026
- Weakness
- CWE-78
- Affected
- collabora/online
- Source
- cve@mitre.org
EPSS moved from 1.2% on 14 October 2026 to 12.3% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
CISA notes
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. https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 ; https://github.com/CollaboraOnline/online/security/advisories/GHSA-g3vx-3m76-fghh ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-110447
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.