CVE-2025-68645 Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion

Exploited in the wild High 8.8 Published 22 Dec 2025 Updated 26 Feb 2026

Unauthenticated attackers can read arbitrary files from the WebRoot directory via Local File Inclusion in the Zimbra Webmail Classic UI.

Exploited in the wild: Since 22 Jan 2026
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-68645?

CVE-2025-68645 is a high-severity path traversal vulnerability in Synacor Zimbra Collaboration Suite, published on 22 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A Local File Inclusion (LFI) vulnerability exists in the Webmail Classic UI of Zimbra Collaboration (ZCS) 10.0 and 10.1 because of improper handling of user-supplied request parameters in the RestFilter servlet. An unauthenticated remote attacker can craft requests to the /h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.

Weakness: CWE-98

Which versions are affected by CVE-2025-68645?

It affects 1 product.

Products include Synacor Zimbra Collaboration Suite.

How do I fix CVE-2025-68645?

No fix has been published for CVE-2025-68645 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 12 Feb 2026.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2025-68645 being exploited?

Yes. Attackers have exploited CVE-2025-68645 in the wild since at least 22 Jan 2026.

Public exploit code: 1 Nuclei template and 7 proofs of concept on GitHub.

All Synacor Zimbra Collaboration Suite vulnerabilities

Sources

Also known as GHSA-xc78-3c4g-m5g9.