Vulnerability details

CVE-2026-110447

Actively exploited

Collabora Online - Built-in CODE Server

CVSS 4.0

9.2Critical

Official 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.

CVSS scores

Score	Version	Source	Vector
9.2Critical	4.0	CVEProject cvelistV5 (CNA) (mitre)	`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

Affected products

Vendor	Product	Versions	Source
Collabora	Collabora Online - Built-in CODE Server	v < 26.4.303	CVEProject cvelistV5 (CNA)

References and advisories

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 government-resource

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Details

Published: 2026-10-14
Last updated: 2026-10-24
State: Published
Assigner (CNA): mitre
Kolun priority: 79 · High

CISA KEV catalog

Date added: 2026-10-23
Due date: 2026-10-26
Used in ransomware: Unknown

Exploit prediction (EPSS)

73.3%

Probability of exploitation in 30 days

99.4%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: Yes
Exploitation: Active
Technical impact: Total

Weaknesses (CWE)

CWE-78
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')