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 first logged attack on September 10. A web shell is a small file that executes any command an...

CVE-2026-110447

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...

CVE-2026-110447

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...

CVE-2026-110447

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...

EUVD-2026-100780

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...

CVE-2026-110447

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...

CVE-2026-110447

The Collabora Online Built-in CODE Server (Nextcloud app richdocumentscode ) is vulnerable to remote code execution (RCE) via an OS command injection in the proxy.php script. The flaw occurs specifically when the CODE server is not running, such as immediately after a restart, crash, or upgrade. ...

VulnCheck KEV: CVE-2026-110447

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...

PT-2026-113607

Name of the Vulnerable Software and Affected Versions Collabora Online Built-in CODE Server richdocumentscode versions prior to 26.4.303 Description An OS command injection issue exists in the proxy.php endpoint of the richdocumentscode app. The flaw occurs when the built-in CODE server is not...

CVE-2026-110447: Improper Neutralization of Special Elements used in an OS Command

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...

CVE-2026-23623

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623: Improper Authorization

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623 Collabora Online vulnerable to Authorization Bypass

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623

CVE-2026-23623 affects Collabora Online and Collabora Online Development Edition. A user with view-only rights and no download privileges can obtain a local copy of a shared file. The vulnerability is triggered by pressing Ctrl+Shift+S, which initiates the file download process despite missing do...

CVE-2026-23623 Collabora Online vulnerable to Authorization Bypass

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

CVE-2026-23623 Collabora Online vulnerable to Authorization Bypass

Collabora Online is a collaborative online office suite based on LibreOffice technology. Prior to Collabora Online Development Edition version 25.04.08.2 and prior to Collabora Online versions 23.05.20.1, 24.04.17.3, and 25.04.7.5, a user with view-only rights and no download privileges can obtai...

PT-2026-6642

Name of the Vulnerable Software and Affected Versions Collabora Online versions prior to 23.05.20.1 Collabora Online versions prior to 24.04.17.3 Collabora Online versions prior to 25.04.7.5 Collabora Online Development Edition versions prior to 25.04.08.2 Description Collabora Online is a...

CVE-2023-31145

Collabora Online is a collaborative online office suite based on LibreOffice technology. This vulnerability report describes a reflected XSS vulnerability with full CSP bypass in Nextcloud installations using the recommended bundle. The vulnerability can be exploited to perform a trivial account...