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Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2026-110447
Collabora Online – Built-in CODE Server OS Command Injection Vulnerability - [Actively Exploited]
Overview
Description

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.

Details
INFO

Published Date :

Oct. 14, 2026, 3:17 a.m.

Last Modified :

Oct. 30, 2026, 4:32 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

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.

Known Ransomware Campaign Use:

Unknown

Notes :

https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 ; https://github.com/CollaboraOnline/online/security/advisories/GHSA-g3vx-3m76-fghh ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-110447

Impact
Affected Products

The following products are affected by CVE-2026-110447 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Collabora online
2 Collabora collabora_online_-_built-in_code_server
: Total Affected Vendor : 1 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 8254265b-2729-46b6-b9e3-3dfca2d5bfca
CVSS 4.0 CRITICAL [email protected]
Solution
Update Collabora Online CODE Server to a patched version to fix OS command injection.
  • Update Collabora Online CODE Server to version 26.4.303 or later.
  • Ensure CODE Server is running to prevent exploitation.
  • Restrict access to proxy.php if updating is not possible.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-110447.

URL Resource
https://github.com/CollaboraOnline/richdocumentscode/issues/354 Issue Tracking
https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-110447 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-110447 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-110447 vulnerability anywhere in the article.

  • The Hacker News
CISA Flags Two Actively Exploited Critical Flaws in Collabora Online and Arista VeloCloud

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Friday added two vulnerabilities impacting Collabora Online Built-in CODE Server and Arista VeloCloud Orchestrator (VCO) to its Know ... Read more

Published Date: Oct 24, 2026 (1 week, 3 days ago)
  • The Hacker News
Hackers Backdoor Nextcloud Servers Through Critical Flaw in Collabora’s Built-in CODE App

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 ... Read more

Published Date: Oct 14, 2026 (2 weeks, 5 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-110447 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Reanalysis by [email protected]

    Oct. 30, 2026

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:a:collabora:online:*:*:*:*:*:nextcloud:*:* versions up to (excluding) 26.4.303 OR *cpe:2.3:a:collabora:collabora_online_-_built-in_code_server:*:*:*:*:*:nextcloud:*:* versions up to (excluding) 26.4.303
  • Initial Analysis by [email protected]

    Oct. 26, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CPE Configuration OR *cpe:2.3:a:collabora:online:*:*:*:*:*:nextcloud:*:* versions up to (excluding) 26.4.303
    Added Reference Type MITRE: https://github.com/CollaboraOnline/richdocumentscode/issues/354 Types: Issue Tracking
    Added Reference Type MITRE: https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516 Types: Vendor Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 24, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T20:04:16.288937Z'}
    Added SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T00:00:00+00:00'}
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Oct. 23, 2026

    Action Type Old Value New Value
    Added Date Added 2026-10-23
    Added Due Date 2026-10-23
    Added Required Action 2026-10-23
    Added Vulnerability Name 2026-10-23
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 23, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T19:31:58.092895Z'}
    Added SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T20:04:16.288937Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 23, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447
    Removed SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T18:42:48.080318Z'}
    Added SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T19:31:58.092895Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 23, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-14T18:05:02.800265Z'}
    Added SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-23T18:42:48.080318Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 14, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-110447', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-14T18:05:02.800265Z'}
  • New CVE Received by [email protected]

    Oct. 14, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-78
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/110xxx/CVE-2026-110447.json">CVE-2026-110447</a>
    Added Reference https://github.com/CollaboraOnline/richdocumentscode/issues/354
    Added Reference https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.2
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact