CSRF in Frankkoenen Plugin Name: Login Register

CVE-2026-1503

The login_register plugin for WordPress is vulnerable to Cross-Site Request Forgery to Stored Cross-Site Scripting in all versions up to, and including, 1.2.0. This is due to missing nonce validation on the settings page and insufficient input sanitization and output escaping on the 'login_register_login_post' parameter. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page via a forged request granted they can trick an administrator into performing an action such as clicking on a link.

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.001 (3.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-1503: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-1503?
CVE-2026-1503 is a medium-severity vulnerability in Frankkoenen Plugin Name: Login Register, classified under Cross-Site Request Forgery (CSRF). CVSS score: 4.3/10. Published 2026-03-21.
How severe is CVE-2026-1503?
Medium severity. CVSS v3 base score is 4.3 out of 10.