Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability

Technical Severity

CVSS v3.1 Metrics

HIGH

8.8 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploitation Likelihood

EPSS Prediction

44.56 %

Predictive Probability

Percentile Rank

97.5 th

Documented as more likely to be exploited than 97.5% of known CVEs.

Detection Date

Jan 22, 2026

Remediation Due

Feb 12, 2026

CISA Catalog Active

Threat Analysis

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.

Remediation Directive

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

External Intelligence

https://wiki.zimbra.com/wiki/Security_Center

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2025-68645