CVE-2026-5347: The HM Books Gallery plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 4.8.0. This is due to the absence of ...

Description

The HM Books Gallery plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 4.8.0. This is due to the absence of capability checks and nonce verification in the admin_init hook that handles the permalink settings update at line 205-209 of wp-books-gallery.php. The vulnerable code checks only for the presence of the 'permalink_structure' POST parameter before updating the 'wbg_cpt_slug' option, without verifying that the request comes from an authenticated administrator. This makes it possible for unauthenticated attackers to modify the custom post type slug for the books gallery, which changes the URL structure for all book entries and can break existing links and SEO rankings.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.32%

24.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

References

Timeline

Published: Apr 24, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-5347?

The HM Books Gallery plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 4.8.0. This is due to the absence of capability checks and nonce verification in the admin_init hook that handles the permalink settings update at line 205-209 of wp-books-gallery.php. The vulnerable code checks only for the presence of the 'permalink_structure' POST parameter before updating the 'wbg_cpt_slug' option, without verifying that the request comes from an authenticated administrator. This makes it possible for unauthenticated attackers to modify the custom post type slug for the books gallery, which changes the URL structure for all book entries and can break existing links and SEO rankings.

How severe is CVE-2026-5347?

CVE-2026-5347 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.

How do I fix CVE-2026-5347?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.