XSS in Blog Floating Button

CVE-2026-15383

The Blog Floating Button WordPress plugin through 1.4.20 does not sanitize or escape the visitor User-Agent header, which it stores through an unauthenticated tracking REST endpoint and later renders unescaped in an administrator report page. This allows an unauthenticated attacker to store a malicious script that executes in the session of any administrator who views the access report, leading to site takeover.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.0% 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-2026-15383: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

  • Blog Floating Button — versions 0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-15383?
CVE-2026-15383 is a medium-severity vulnerability in Blog Floating Button, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-08-03.
How severe is CVE-2026-15383?
Medium severity. CVSS v3 base score is 6.1 out of 10.