WordPress version 4.9.8 and earlier contains a CWE-20 Input Validation vulnerability in thumbnail processing that can result in remote code execution due to an incomplete fix for CVE-2017-1000600. This attack appears to be exploitable via thumbnail upload by an authenticated user and may require additional plugins in order to be exploited however this has not been confirmed at this time.
Conclusion & alert: CVE-2018-1000773 is rated Moderate Risk (62.9/100): CVSS High severity, with high exploitation likelihood (EPSS 7.26%, 94th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize 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 | 2026-06-15 | 27.77% | 7.26% | -20.50% |
| 2 | 2026-03-23 | 28.75% | 27.77% | -0.98% |
| 3 | 2026-03-12 | — | 28.75% | — |
Full EPSS history (50 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.0 | HIGH |
|
2.8 | 5.9 | [email protected] |
| 6.5 | 2.0 | MEDIUM |
|
8.0 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
ubuntu
|
low | CVE-2018-1000773 low priority: Ubuntu including 1 source packages (wordpress), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 11, needs-triage 7, DNE 1. | https://ubuntu.com/security/CVE-2018-1000773 |
| URL | Tags |
|---|---|
| http://www.securityfocus.com/bid/105306 | Third Party Advisory VDB Entry |
| https://www.theregister.co.uk/2018/08/20/php_unserialisation_wordpress_vuln/ | Third Party Advisory |
| https://youtu.be/GePBmsNJw6Y?t=1763 | Third Party Advisory |