ID :ISA-2026-121
Critical alertActiveCVSS 9.2/10IservicesCSIRT

Remote code execution affecting Collabora Online Built-in CODE Server

Executive Summary

A vulnerability affecting Collabora Online Built-in CODE Server (Nextcloud richdocumentscode application) would allow an unauthenticated attacker to remotely execute arbitrary code on affected systems.

Published on October 15, 2026 at 01:00 AM by Iservices Csirt15 views

Description

Technical context and vulnerability details

Collabora Online Built-in CODE Server is a component integrated into the Nextcloud application, allowing collaborative editing of documents. This product is affected by a vulnerability labeled CVE-2026-110447 which results from an injection of system commands in the proxy.php script relaying HTTP requests between Nextcloud and the local CODE server. Exploitation of this vulnerability would allow an unauthenticated attacker to execute arbitrary commands on the system with web server privileges. Operation is only possible when the CODE server is not running, in particular after a restart. It is classified critical with a severity score of 9.2 according to CVSS V4.0.

Potential Risks & Impact

Potential consequences upon exploitation

  • Remote Arbitrary Code Execution;
  • Compromise of system integrity;
  • Data privacy breach;
  • Data integrity breach;

Affected systems

Products, components and targeted versions

  • Collabora Online Built-in CODE Server (Nextcloud richdocumentscode app) versions earlier than 26.4.303;

Recommended Remediations & Actions

Immediate actions and recommended mitigations

  • Update Collabora Online Built-in CODE Server (Nextcloud richdocumentscode app) to version 26.4.303 or later;

Advisory Specifications

ISA-2026-121
CVSS scoreCRITICAL
9.2/ 10.0
0.0 (Low)5.0 (Med)10.0 (Crit)
PriorityCritical
StatusActive
Typesecurite
Published onOctober 15, 2026 at 01:00 AM
OrigineIservicesCSIRT
Audience15 views

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