XSS in Olivesystem 診断ジェネレータ作成プラグイン

CVE-2026-5293

The 診断ジェネレータ作成プラグイン (Diagnosis Generator) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'js' parameter in versions up to and including 1.4.16. This is due to missing authorization checks and insufficient input sanitization in the themeFunc() function. The function is hooked to 'admin_init' and processes theme update requests without verifying user capabilities, allowing any authenticated user (including subscribers) to save malicious JavaScript to theme files. Additionally, the save() function uses stripslashes() which removes WordPress's magic quotes protection. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in theme files that will execute whenever a user accesses a page containing the diagnosis form shortcode.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (32.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 32.6% 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-2026-5293: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5293?
CVE-2026-5293 is a medium-severity vulnerability in Olivesystem 診断ジェネレータ作成プラグイン, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-05-20.
How severe is CVE-2026-5293?
Medium severity. CVSS v3 base score is 6.4 out of 10.