Symantec Messaging Gateway, prior to 10.7.3, may be susceptible to a cross-site scripting (XSS) exploit, which is a type of issue that can enable attackers to inject client-side scripts into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to potentially bypass access controls such as the same-origin policy.
Conclusion & alert: CVE-2019-18378 is rated Low Risk (36.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.73%). 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 | 0.32% | 0.73% | +0.41% |
| 2 | 2025-11-21 | 0.49% | 0.32% | -0.18% |
| 3 | 2025-11-18 | — | 0.49% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.8 | 3.1 | MEDIUM |
|
1.7 | 2.7 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| symantec | messaging_gateway | < 10.7.3 | cpe:2.3:a:symantec:messaging_gateway:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://support.symantec.com/us/en/article.SYMSA1501.html | Vendor Advisory |