CVE-2025-68645 Synacor Zimbra Collaboration Suite (ZCS): software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Feb 12, 2026
What to do
- Install Synacor's security update for Zimbra Collaboration Suite (ZCS). If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability
- Product
- Synacor Zimbra Collaboration Suite (ZCS)
- CISA description
- Synacor Zimbra Collaboration Suite (ZCS) contains a PHP remote file inclusion vulnerability that could allow for remote attackers to craft requests to the /h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.
- Type of flaw
- Software flaw (CWE-98)
- Confirmed exploited
- Jan 22, 2026
- US federal patch deadline
- Feb 12, 2026
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Answering about CVE-2025-68645 ·
Questions about CVE-2025-68645
Is CVE-2025-68645 being exploited?
Yes. CISA added CVE-2025-68645 to its Known Exploited Vulnerabilities catalog on Jan 22, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2025-68645?
Install Synacor's security update for Zimbra Collaboration Suite (ZCS). If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2025-68645?
Only if you use Synacor Zimbra Collaboration Suite (ZCS). Aimed mostly at company systems — you are affected through the companies you use, not your own phone.