Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-110447

Collabora Online - Built-in CODE Server Remote Code Execution

Collabora Online - Built-in CODE Server · affected before 26.4.303

Watch CVE-2026-110447 Browse KEV feed
Severity
CVSS 9.2 · Critical
Confidence
High
Exploit status
Exploited in the wild
EPSS
1.2%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-110447 is an unauthenticated vulnerability affecting Collabora Online - Built-in CODE Server. Collabora Online Built-in CODE Server before 26.4.303 (richdocumentscode), a Nextcloud app, allows remote code...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

Collabora Online - Built-in CODE Server affected before 26.4.303.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Collabora Online - Built-in CODE Server Remote Code Execution

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.

Collabora Affected
Collabora Online - Built-in CODE Server richdocumentscode
Before 26.4.303
View vendor advisory (opens in new tab)
Published
14 Oct 2026
Exploitation Reported
14 Oct 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

php

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 14 Oct 2026

A trusted third party reported exploitation.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-10-14 02:40 UTC
The Hacker News 2026-10-14 18:31 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.2 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

1.2%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') CWE-78

Recent mention · The Hacker News

Hackers Backdoor Nextcloud Servers Through Critical Flaw in Collabora’s Built-in CODE App

Swati KhandelwalOct 14, 2026Vulnerability / Malware Attackers exploited a flaw in an optional Nextcloud app, Collabora Online - Built-in CODE Server, to plant web shells on Nextcloud servers. Three administrators reported the issue on GitHub, with the first logged attack on...

Read full advisory

Timeline

From disclosure to observed exploitation

  1. 18:31 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  2. 02:40 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  3. 02:27 UTC

    CVE published

    Vulnerability disclosed publicly

  4. 02:27 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-110447

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-110447",
  "confidence": "High",
  "cvss_score": 9.2,
  "cvss_estimated": false,
  "epss_score": 0.01225,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}