CVE-2025-68645

Synacor Zimbra Collaboration Suite (ZCS) contains a PHP remote file inclusion (RFI) flaw (CWE-98) reachable through its /h/rest endpoint. By sending crafted requests to /h/rest, a remote attacker can influence the application's internal request dispatching and cause the server to include arbitrary files from the WebRoot directory, potentially exposing sensitive file content or executing attacker-influenced file content reachable there. An attacker who abuses this flaw may gain information disclosure or further compromise of the ZCS server; the available data does not specify authentication requirements or confirm full remote code execution. Any organization running Zimbra Collaboration Suite, especially internet-facing ZCS email and collaboration servers, is potentially affected, though specific affected version ranges were not provided in the available data. The flaw was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-01-22, indicating confirmed exploitation in the wild, and EPSS assigns a 49.4% probability of exploitation within 30 days (99th percentile); no public proof-of-concept is known.

What to do: Apply the patched ZCS release per Synacor's/Zimbra's advisory (specific patched versions were not provided in the available data) and follow CISA KEV required actions, including applicable BOD 22-01 guidance for federal agencies. Review access logs for crafted or anomalous requests to /h/rest and restrict internet exposure of ZCS endpoints until the patch is deployed. Ransomware association is unknown, so treat exploitation activity as potentially preparatory to broader compromise.