Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass Vulnerability
Synacor Zimbra Collaboration Suite (ZCS) contains an authentication bypass vulnerability in MailboxImportServlet. This vulnerability was chained with CVE-2022-27925 which allows for unauthenticated remote code execution.
- Vendor
- Synacor
- Product
- Zimbra Collaboration Suite (ZCS)
- CVSS
- 9.8
- EPSS (exploit probability)
- 91.9%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2022-37042 being exploited?
Yes. CISA added CVE-2022-37042 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 91.9% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Synacor Zimbra Collaboration Suite (ZCS) CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-73570 Zimbra ZCS SNMP Command Injection — Unauthenticated RCEwrite-up | [ HIGH ] | 8.9 | 71.7% | |
| CVE-2025-48700 Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability | [ MEDIUM ] | 6.1 | 1.7% | |
| CVE-2025-66376 Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability | [ HIGH ] | 7.2 | 20.2% | |
| CVE-2020-7796 Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability | [ CRITICAL ] | 9.8 | 84.4% | |
| CVE-2025-68645 Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability | [ HIGH ] | 8.8 | 48.9% | |
| CVE-2025-27915 Synacor Zimbra Collaboration Suite (ZCS) Cross-site Scripting Vulnerability | [ MEDIUM ] | 5.4 | 4.1% | |
| CVE-2019-9621 Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (SSRF) Vulnerability | [ HIGH ] | 7.5 | 81.0% | |
| CVE-2024-27443 Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability | [ MEDIUM ] | 6.1 | 24.6% |