Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability (CVE-2025-68645)
Severity: high · Patch status: unknown · Since 2026-01-22 · CVE-2025-68645
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. CISA added CVE-2025-68645 to its Known Exploited Vulnerabilities catalog on Jan 22, 2026, which means attackers are exploiting it in the wild.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Feb 12, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch