Description
The Seraphinite Accelerator plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'seraph_accel_prep' parameter in versions up to, and including, 2.29.15. This is due to the CacheExtractPreparePageParams() function using PHP's loose inequality operator (!=) to compare the expected HMAC string against the JSON-decoded 'nonce' value — supplying the JSON boolean true causes any non-empty HMAC string to compare as loosely equal, bypassing the signature check — combined with insufficient output escaping in the _CbContentFinishSkip() function, which concatenates the attacker-controlled 'selfTest' field directly into the HTML response body. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.
References9
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags…
- plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&repo…
- plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&repo…
- www.wordfence.com/threat-intel/vulnerabilities/id/5aeea62b-bd6c…
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 1% percentile: 57 · as of 13 November 2026
- CWE
- CWE-79
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