---
title: "CVE-2026-110447: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-110447/
description: "CVE-2026-110447 (Collabora Collabora Online – Built-in CODE Server): Exploited in the wild (CISA KEV). Collabora Online Built-in CODE Server before 26.4.303…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-14
date_modified: 2026-10-23
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-110447"
kev: true
cvss: 9.2
epss: 0.01225
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-110447: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Collabora Collabora Online – Built-in CODE Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-10-23, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-10-26 ; treat that as the outer limit, not the target.
- EPSS 1.2% , percentile 69: FIRST’s model estimates a 1.2% chance of exploitation activity in the next 30 days, higher than 69% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it 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.

## Affected products (CVE record)

- Collabora Collabora Online - Built-in CODE Server: < 26.4.303

## Severity

- mitre CVSS 4.0: 9.2 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: added 2026-10-23; federal due date 2026-10-26. Known ransomware use: Unknown.
- CISA 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.
- CISA SSVC assessment: exploitation active , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-23): 1.23% probability of exploitation activity in the next 30 days; percentile 69.

## Sources

- [help.nextcloud.com](https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516)
- [Listed in CISA KEV notes (github.com)](https://github.com/CollaboraOnline/online/security/advisories/GHSA-g3vx-3m76-fghh)
- [CVE.org record CVE-2026-110447](https://www.cve.org/CVERecord?id=CVE-2026-110447)
- [NVD entry CVE-2026-110447](https://nvd.nist.gov/vuln/detail/CVE-2026-110447)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk)
- [Listed in CISA KEV notes (cisa.gov)](https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk)
- [github.com](https://github.com/CollaboraOnline/richdocumentscode/issues/354)

---
Source page: https://erroneo.us/security/cve/CVE-2026-110447/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt