CVE-2026-110447: collabora collabora_online_-_built-in_code_server

CVSS 9.8 (critical) · listed as exploited by CISA since 2026-10-23 · published 2026-10-14

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.

Affected products (NVD): collabora collabora_online_-_built-in_code_server

Fixed in (NVD): 26.4.303

Weakness: CWE-78

Source: NVD CVE-2026-110447

References

• https://github.com/CollaboraOnline/richdocumentscode/issues/354
• https://help.nextcloud.com/t/to-collabora-built-in-user-update-asap/250516
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-110447

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