dbcve.org
CollaborationApplication · Zimbra

CVE-2025-27914

MEDIUM · 5.4 CVSS v3.1 Published 2025-03-12
Fix available
A fix is available. Upgrade to 10.0.11 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A Reflected Cross-Site Scripting (XSS) vulnerability exists in the /h/rest endpoint, allowing authenticated attackers to inject and execute arbitrary JavaScript in a victim's session. Exploitation requires a valid auth token and involves a crafted URL with manipulated query parameters that triggers XSS when accessed by a victim.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Reflected XSS in Zimbra Collaboration's /h/rest endpoint affecting versions 9.0, 10.0, and 10.1. Authenticated attackers can inject arbitrary JavaScript via crafted query parameters in URLs, executing in victims' sessions when accessed.

MitigationImplement contextual output encoding and input validation on the /h/rest endpoint; add Content-Security-Policy headers; ensure session cookies use HttpOnly/Secure flags. Upgrade to vendor-patched version when available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CollaborationApplication
Affected:>= 10.0.0, < 10.0.11= 9.0.0= 10.1.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate Zimbra installation and determine version
    Run 'zmcontrol -v' or check /opt/zimbra/.git_version to find the installed Zimbra Collaboration version
    Affected if The installed version matches 9.0.0, 10.0.0 through 10.0.10, or 10.1.0
  2. Confirm the /h/rest endpoint is accessible
    Attempt to access https://your-zimbra-host/h/rest or http://your-zimbra-host/h/rest and verify the endpoint responds
    Affected if The endpoint returns any HTTP response (even an error or redirect) indicating it is exposed
  3. Verify authentication configuration for /h/rest
    Check whether the /h/rest endpoint requires authentication by reviewing Zimbra proxy and web configuration files in /opt/zimbra/conf/
    Affected if The endpoint is accessible without requiring valid session authentication, or allows authenticated users to pass arbitrary query parameters
  4. Review web mail logs for suspicious /h/rest requests
    Examine /opt/zimbra/log/mailbox.log or access logs for unusual query parameter patterns in requests to /h/rest endpoint
    Affected if Logs contain requests to /h/rest with suspicious or encoded characters in URL parameters that may indicate exploitation attempts

You are affected if Zimbra Collaboration versions 9.0.0, 10.0.0-10.0.10, or 10.1.0 are installed and the /h/rest endpoint is exposed to potential authenticated attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.11 or later
Fixed in 10.0.11
Interim mitigation

Implement contextual output encoding and input validation on the /h/rest endpoint; add Content-Security-Policy headers; ensure session cookies use HttpOnly/Secure flags. Upgrade to vendor-patched version when available.

Recommended fix Moderate confidence

Zimbra Collaboration 10.0.11 (for 10.0.x versions); contact Zimbra for 9.0.0 and 10.1.0 specific patches

  1. 1. Obtain the fixed Zimbra Collaboration version 10.0.11 from official Zimbra channels
  2. 2. Review Zimbra upgrade documentation for your current version
  3. 3. Schedule maintenance window as upgrades require downtime
  4. 4. Backup current Zimbra configuration and mail data
  5. 5. Stop all Zimbra services before upgrade
  6. 6. Install Zimbra Collaboration 10.0.11 using the official upgrade path for your current version
  7. 7. Verify all services start correctly post-upgrade
  8. 8. Test the /h/rest endpoint to confirm XSS is no longer present
Caveat Review Zimbra 10.0.11 release notes for any configuration or feature changes; test thoroughly in staging before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Collaboration Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-27914 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-27914 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data