CISA Adds Exploited Collabora Built-in CODE Flaw to KEV

P1 — VALIDATE AND UPDATECritical · 9.2 (CVSS v4.0)EXPLOITATION: CONFIRMED IN CISA KEV

Quick Answer

CISA added Collabora Built-in CODE CVE-2026-110447 to KEV on October 23. Inventory Nextcloud apps, preserve evidence, update richdocumentscode to 26.4.303 or later or remove it, complete required forensic triage by October 26 where applicable, validate service behavior, and retain proof.

Confirm Scope And Apply The Supported Remediation

What to do now: Inventory Nextcloud deployments, richdocumentscode installation and enabled state, exact app and Nextcloud releases, restart history, web exposure, owners, logs, backups, and recovery dependencies. Match the optional Built-in CODE app to releases before 26.4.303. Standalone Collabora Online is unaffected; do not infer compromise solely from app presence, and do not treat a disabled but installed vulnerable app as safely remediated. Preserve evidence, then update richdocumentscode to 26.4.303 or later or remove the app entirely. Upgrade end-of-life Nextcloud 29 and earlier or remove the app, and complete CISA-required forensic triage by October 26 where applicable. Confirm the app version or removal, test Nextcloud document workflows, inspect relevant web, process, file-integrity and network evidence for unauthorized commands or persistence, validate backups and recovery, and retain results.

Open the authoritative advisory

Last verified: 2026-10-24 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.

Scope And Authority

Product scopeCollabora Online - Built-in CODE Server app for Nextcloud (richdocumentscode)
AdvisoryGHSA-g3vx-3m76-fghh / CISA KEV: CVE-2026-110447
CVECVE-2026-110447
Authoritative release date2026-10-23 19:30:18.920900 UTC
Authority revision date2026-10-23 19:30:18.920900 UTC
Affected versionsrichdocumentscode releases before 26.4.303. Standalone Collabora Online servers are not affected; the command-injection path is reachable while the built-in CODE server is not running, including around restart, upgrade, or crash conditions.
Fixed versionrichdocumentscode 26.4.303 or later, or removal of the Built-in CODE app; end-of-life Nextcloud 29 and earlier must be upgraded or the app removed
CVSS base score9.2 (CVSS v4.0)
CVSS severityCritical
Exploitation statusKnown exploited: confirmed by CISA KEV; ransomware campaign use is Unknown.; no exploitation claim is inferred.

What Changed

Collabora fixed unauthenticated OS command injection in the Built-in CODE proxy. CISA added CVE-2026-110447 to KEV, confirming exploitation and requiring forensic triage for covered organizations.

What To Validate Now

  1. Inventory. Inventory Nextcloud deployments, richdocumentscode installation and enabled state, exact app and Nextcloud releases, restart history, web exposure, owners, logs, backups, and recovery dependencies.
  2. Establish applicability. Match the optional Built-in CODE app to releases before 26.4.303. Standalone Collabora Online is unaffected; do not infer compromise solely from app presence, and do not treat a disabled but installed vulnerable app as safely remediated.
  3. Remediate. Preserve evidence, then update richdocumentscode to 26.4.303 or later or remove the app entirely. Upgrade end-of-life Nextcloud 29 and earlier or remove the app, and complete CISA-required forensic triage by October 26 where applicable.
  4. Validate. Confirm the app version or removal, test Nextcloud document workflows, inspect relevant web, process, file-integrity and network evidence for unauthorized commands or persistence, validate backups and recovery, and retain results.
  5. Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.

Operational Cautions

Known exploitation does not prove a particular server was compromised. Preserve evidence before remediation, investigate persistence independently of patch state, and keep incident-response findings out of general change tickets when sensitive.

Evidence To Retain

  • Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
  • UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
  • Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.

Related TechGeeks Resources

Authoritative References

Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.