wp-admin/user-new.php in WordPress before 4.9.1 sets the newbloguser key to a string that can be directly derived from the user ID, which allows remote attackers to bypass intended access restrictions by entering this string.
Conclusion & alert: CVE-2017-17091 is rated High Risk (72.9/100): CVSS High severity, with high exploitation likelihood (EPSS 8.20%, 94th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.77% over the last day, indicating growing attacker interest. 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 | 3.43% | 8.20% | +4.77% |
| 2 | 2026-05-24 | 4.48% | 3.43% | -1.05% |
| 3 | 2026-03-04 | — | 4.48% | — |
Full EPSS history (41 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 |
|---|---|---|---|
debian
|
not yet assigned | CVE-2017-17091 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-2017-17091 |
ubuntu
|
medium | CVE-2017-17091 medium priority: Ubuntu including 1 source packages (wordpress), 21 status rows across 21 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial, zesty): not-affected 16, ignored 2, DNE 1, needed 1, released 1. | https://ubuntu.com/security/CVE-2017-17091 |
| URL | Tags |
|---|---|
| http://www.securityfocus.com/bid/102024 | Third Party Advisory VDB Entry |
| https://codex.wordpress.org/Version_4.9.1 | Patch Release Notes |
| https://github.com/WordPress/WordPress/commit/eaf1cfdc1fe0bdffabd8d879c591b864d833326c | Patch |
| https://lists.debian.org/debian-lts-announce/2017/12/msg00019.html | |
| https://wordpress.org/news/2017/11/wordpress-4-9-1-security-and-maintenance-release/ | Release Notes |
| https://wpvulndb.com/vulnerabilities/8969 | Third Party Advisory VDB Entry |
| https://www.debian.org/security/2018/dsa-4090 |