CVE-2025-68645: Synacor Zimbra Collaboration Suite file inclusion in RestFilter servlet

CVE-2025-68645 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2025-12-22

Synacor Zimbra Collaboration Suite, a widely used enterprise email and collaboration platform, contains a critical security flaw in its classic web interface. An attacker can exploit this vulnerability to access sensitive internal files, potentially leading to the exposure of private data or system compromise. This vulnerability is currently being exploited in the wild, making immediate patching essential to protect corporate communications and operations.

Technologies: Synacor Zimbra Collaboration Suite, Synacor Zimbra Collaboration Suite (ZCS). Vendors: Synacor.

Quick answers

Is CVE-2025-68645 exploited in the wild?
Yes. CVE-2025-68645 is known to be exploited in the wild, first recorded on 22 January 2026. Treat it as urgent.
How severe is CVE-2025-68645?
Critical severity, with a CVSS score of 8.8, published 22 December 2025.
Which products and versions are affected?
Synacor Zimbra Collaboration Suite 10.0.0 to 10.0.17, 10.1.0 to 10.1.12.
Is there a fix for CVE-2025-68645?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2025-68645 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2025-68645?
Check whether you run Synacor Zimbra Collaboration Suite or Synacor Zimbra Collaboration Suite (ZCS) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A Local File Inclusion (LFI) vulnerability exists in the Webmail Classic UI of Zimbra Collaboration (ZCS) versions 10.0 and 10.1. The flaw is rooted in the improper handling of user-supplied request parameters within the RestFilter servlet. An unauthenticated remote attacker can craft malicious requests to the /h/rest endpoint to manipulate internal request dispatching. This allows the inclusion and potentially the execution of arbitrary files located within the WebRoot directory. The vulnerability is tracked as CWE-98 and has been observed in active exploitation. Patches are available in ZCS versions 10.0.18 and 10.1.13.

Affected products

  • Synacor Zimbra Collaboration Suite (ZCS) 10.0.0 to 10.0.17, 10.1.0 to 10.1.12

Timeline

  • 2025-12-22: disclosed: Initial CVE publication
  • 2026-01-22: kev added: Added to CISA Known Exploited Vulnerabilities catalog
  • 2026-01-22: advisory: CISA advisory published

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