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

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• 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.

CISA’s 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.

Weakness type: CWE-78.

Product: Collabora Collabora Online – Built-in CODE Server · Assigned by: mitre · Published: 2026-10-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• 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.

Timeline

• 2026-10-14 — CVE record published by mitre
• 2026-10-23 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-10-23 — CVE record last updated
• 2026-10-26 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. help.nextcloud.com help.nextcloud.com
2. Listed in CISA KEV notes (github.com) github.com

Vulnerability records

1. CVE.org record CVE-2026-110447 cve.org
2. NVD entry CVE-2026-110447 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

Other references from the CVE record and advisory

1. github.com github.com

All exploited Collabora vulnerabilities · Today’s Security Digest