CVE-2025-66208: CollaboraOnline online · OS Command Injection
Affects CollaboraOnline onlineSource CVE Database V5
Not known to be exploited · CVSS 7.2 High : upgrade to 25.04.702 soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 1.8% chance of exploitation in 30 days – higher than 78% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 25.04.702
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/E:UExploitation evidence
Disclosed: evidence found.
CVE published 3 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade collaboraonline/online to 25.04.702.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubcollaboraonline/onlinepkg:github/collaboraonline/onlineOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
European organizations should immediately upgrade Collabora Online to version 25.04.702 or later to remediate this vulnerability. Until patching is possible, administrators should restrict access to the proxy.php endpoint via network controls such as IP whitelisting or firewall rules, especially blocking access from untrusted networks. Deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious command injection patterns targeting proxy.php can provide temporary protection. Monitoring logs for unusual command execution attempts or proxy.php access patterns is critical for early detection. Organizations should also review and harden the configuration of any intermediate reverse proxies to minimize exposure. Regularly auditing and limiting permissions of the Collabora Online service account can reduce potential damage from exploitation. Finally, integrating vulnerability management processes to ensure timely updates of collaboration software is essential to prevent exploitation of similar future vulnerabilities.
Description
CVE-2025-66208 is a high-severity OS command injection vulnerability affecting Collabora Online's built-in CODE Server (richdocumentscode proxy) in versions prior to 25.04.702. This flaw allows unauthenticated remote attackers to execute arbitrary OS commands via the proxy.php interface, particularly when used with Nextcloud and an intermediate reverse proxy. The vulnerability arises from improper neutralization of special elements in OS commands (CWE-78). No user interaction or privileges are required, and the vulnerability has not yet been observed exploited in the wild. The issue is fixed in version 25.04.702.