CVE-2025-66208Network attack vector

Remote command execution via unescaped Host header

Published Dec 3, 2025 · Updated Dec 3, 2025

OS command injection in Collabora Online before 25.04.702 allows remote attackers to execute commands through the richdocumentscode proxy. The proxy.php startCoolwsd function inserts the request-derived HTTP_HOST value unescaped into a bash -c launch command used to set net.lok_allow.host. Exploitation requires the built-in CODE Server behind an intermediate reverse proxy that insecurely trusts X-Forwarded-Host; default deployments and standalone servers are unaffected.

CVSS severity9.8
Critical
EPSS probability1.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in Collabora Online before 25.04.702 allows remote attackers to execute commands through the richdocumentscode proxy. The proxy.php startCoolwsd function inserts the request-derived HTTP_HOST value unescaped into a bash -c launch command used to set net.lok_allow.host. Exploitation requires the built-in CODE Server behind an intermediate reverse proxy that insecurely trusts X-Forwarded-Host; default deployments and standalone servers are unaffected.

The record

CVE
CVE-2025-66208
Published
Dec 3, 2025
Updated
Dec 3, 2025
Vendor
Collabora Productivity
Product
Collabora Online
Classifications
CWE-78, T1059.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 25.04.702

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Collabora Productivity · Collabora Onlineversion=< 25.04.702

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.2GitHub, Inc.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:U/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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Unix Shell

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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