CVE-2026-6401

CVE-2026-6401 is a medium-severity vulnerability with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-352.

Key facts

Description

The Bottom Bar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to and including 0.1.7. This is due to missing nonce verification on the plugin's settings update forms handled in bottom-bar-admin.php. None of the three settings forms (main settings, sharing services, restore defaults) include a wp_nonce_field(), and the server-side processing code never calls check_admin_referer() or any equivalent nonce validation before processing POST data and calling update_option(). This makes it possible for unauthenticated attackers to trick a logged-in administrator into submitting a crafted request that updates plugin configuration options, such as changing the language, maximum post counts, or enabled sharing services.

Frequently asked questions

What is CVE-2026-6401?
The Bottom Bar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to and including 0.1.7. This is due to missing nonce verification on the plugin's settings update forms handled in bottom-bar-admin.php. None of the three settings forms (main settings, sharing services, restore defaults) include a wp_nonce_field(), and the server-side processing code never calls check_admin_referer() or any equivalent nonce validation before processing POST data and calling update_option(). This makes it possible for unauthenticated attackers to trick a logged-in administrator into submitting a crafted request that updates plugin configuration options, such as changing the language, maximum post counts, or enabled sharing services.
How severe is CVE-2026-6401?
CVE-2026-6401 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-6401 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-6401?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-6401 have an EU (EUVD) identifier?
Yes. CVE-2026-6401 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31039.
When was CVE-2026-6401 published?
CVE-2026-6401 was published on 2026-05-20 and last updated on 2026-06-17.

References

Other CWE-352 (Cross-Site Request Forgery (CSRF)) vulnerabilities

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