WordPress before 4.9.2 has XSS in the Flash fallback files in MediaElement (under wp-includes/js/mediaelement).
Conclusion & alert: CVE-2018-5776 is rated Moderate Risk (53/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.40%). Mandatory action: Review affected assets and schedule remediation.
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 | 2026-06-29 | 2.45% | 2.40% | -0.05% |
| 2 | 2026-06-15 | 2.83% | 2.45% | -0.38% |
| 3 | 2026-05-24 | — | 2.83% | — |
Full EPSS history (40 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.1 | 3.0 | MEDIUM |
|
2.8 | 2.7 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2018-5776 not yet assigned priority: Debian including 1 source packages (wordpress), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2018-5776 |
ubuntu
|
medium | CVE-2018-5776 medium priority: Ubuntu including 1 source packages (wordpress), 20 status rows across 20 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 12, needs-triage 7, DNE 1. | https://ubuntu.com/security/CVE-2018-5776 |
| URL | Tags |
|---|---|
| https://codex.wordpress.org/Version_4.9.2 | Product Vendor Advisory |
| https://github.com/WordPress/WordPress/commit/3fe9cb61ee71fcfadb5e002399296fcc1198d850 | Patch |
| https://wordpress.org/news/2018/01/wordpress-4-9-2-security-and-maintenance-release/ | Release Notes Vendor Advisory |
| https://wpvulndb.com/vulnerabilities/9006 | Third Party Advisory |