An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A Reflected Cross-Site Scripting (XSS) vulnerability exists in the /h/rest endpoint, allowing authenticated attackers to inject and execute arbitrary JavaScript in a victim's session. Exploitation requires a valid auth token and involves a crafted URL with manipulated query parameters that triggers XSS when accessed by a victim.
Conclusion & alert: CVE-2025-27914 is rated Low Risk (27.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%). 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% | 0.24% | +0.20% |
| 2 | 2026-04-20 | 0.05% | 0.05% | -0.01% |
| 3 | 2025-12-06 | — | 0.05% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.4 | 3.1 | MEDIUM |
|
2.3 | 2.7 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| zimbra | collaboration | >= 10.0.0, < 10.0.11 | cpe:2.3:a:zimbra:collaboration:*:*:*:*:*:*:*:* |
| zimbra | collaboration | 9.0.0 | cpe:2.3:a:zimbra:collaboration:9.0.0:-:*:*:*:*:*:* |
| zimbra | collaboration | 10.1.0 | cpe:2.3:a:zimbra:collaboration:10.1.0:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.11#Security_Fixes | Release Notes |
| https://wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy | Technical Description |