CVE-2026-6203
MediumUser Registration & Membership <= 5.1.4 - Unauthenticated Open Redirect via 'redirect_to_on_logout' Parameter
Published Apr 13, 2026 · Updated Apr 24, 2026 · Also known as 020bed37-9544-49b7-941d-3b7f509fdfdf, WORDFENCE-020bed37-9544-49b7-941d-3b7f509fdfdf
Key Facts
Routine patching- CVE-2026-6203 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting user-registration (wordpress-plugin), User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 0.6% probability of exploitation in the next 30 days.
- Fixed versions are available, including user-registration 5.1.5.
- Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
0.6%
Higher than 45.4% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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Description
The User Registration & Membership plugin for WordPress is vulnerable to Open Redirect in versions up to and including 5.1.4. This is due to insufficient validation of user-supplied URLs passed via the 'redirect_to_on_logout' GET parameter before redirecting users.
The redirect_to_on_logout GET parameter is passed directly to WordPress's wp_redirect() function instead of the domain-restricted wp_safe_redirect(). While esc_url_raw() is applied to sanitize malformed URLs, it does not restrict the redirect destination to the local domain, allowing an attacker to craft a specially formed link that redirects users to potentially malicious external URLs after logout, which could be used to facilitate phishing attacks.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| user-registrationwordpress-plugin | See advisory | 5.1.5 |
| User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder | See advisory | n/a |
Patched Releases
user-registration
5.1.5
Timeline
Publicly disclosed
Apr 13, 2026
Last updated
Apr 24, 2026
Weakness Type
- CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
References
FAQ
Common Questions.
The User Registration & Membership plugin for WordPress is vulnerable to Open Redirect in versions up to and including 5.1.4.
Affected: user-registration (wordpress-plugin); User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including user-registration 5.1.5.
Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
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