CVE-2026-5347

MEDIUM
Published Apr 24, 2026 Modified Apr 24, 2026 CWE-862

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.

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CVSS v3.1 Score

5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0002
Probability of exploitation
0.05%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-862 Missing Authorization

References

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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2026-5347? +
CVE-2026-5347 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-5347? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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