An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A Cross-Site Request Forgery (CSRF) vulnerability exists in Zimbra Web Client due to the issuance of authentication tokens without CSRF protection during certain account state transitions. Specifically, tokens generated after operations such as enabling two-factor authentication or changing a password may lack CSRF enforcement. While such a token is active, authenticated SOAP requests that trigger token generation or state changes can be performed without CSRF validation. An attacker could exploit this by inducing a victim to submit crafted requests, potentially allowing sensitive account actions such as disabling two-factor authentication. The issue is mitigated by ensuring CSRF protection is consistently enforced for all issued authentication tokens.
Conclusion & alert: CVE-2026-33373 is rated Low Risk (38.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.20%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.05% | 0.20% | +0.15% |
| 2 | 2026-05-01 | 0.03% | 0.05% | +0.02% |
| 3 | 2026-03-31 | — | 0.03% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| synacor | zimbra_collaboration_suite | >= 10.0.0, < 10.0.18 | cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* |
| synacor | zimbra_collaboration_suite | >= 10.1.0, < 10.1.13 | cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://wiki.zimbra.com/wiki/Security_Center | Release Notes Vendor Advisory |
| https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.18#Security_Fixes | Release Notes |
| https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.13#Security_Fixes | Release Notes |
| https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy | Product |