GHSA-FF83-HFR5-72CH

Vulnerability from github – Published: 2026-08-05 09:31 – Updated: 2026-08-05 09:31
VLAI
Details

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.

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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{
  "affected": [],
  "aliases": [
    "CVE-2026-17532"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T08:16:32Z",
    "severity": "MODERATE"
  },
  "details": "The Seraphinite Accelerator plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the \u0027seraph_accel_prep\u0027 parameter in versions up to, and including, 2.29.15. This is due to the CacheExtractPreparePageParams() function using PHP\u0027s loose inequality operator (!=) to compare the expected HMAC string against the JSON-decoded \u0027nonce\u0027 value \u2014 supplying the JSON boolean true causes any non-empty HMAC string to compare as loosely equal, bypassing the signature check \u2014 combined with insufficient output escaping in the _CbContentFinishSkip() function, which concatenates the attacker-controlled \u0027selfTest\u0027 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.",
  "id": "GHSA-ff83-hfr5-72ch",
  "modified": "2026-08-05T09:31:16Z",
  "published": "2026-08-05T09:31:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-17532"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.15/cache.php#L76"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.15/cache_ex.php#L838"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.15/common.php#L6036"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.18/cache.php#L76"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.18/cache_ex.php#L838"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/seraphinite-accelerator/tags/2.29.18/common.php#L6036"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?sfp_email=\u0026sfph_mail=\u0026reponame=\u0026new=3624461%40seraphinite-accelerator%2Ftrunk%2Fcache_ex.php\u0026old=3619618%40seraphinite-accelerator%2Ftrunk%2Fcache_ex.php\u0026sfp_email=\u0026sfph_mail="
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?sfp_email=\u0026sfph_mail=\u0026reponame=\u0026new=3624461%40seraphinite-accelerator%2Ftrunk%2Fcommon.php\u0026old=3619618%40seraphinite-accelerator%2Ftrunk%2Fcommon.php\u0026sfp_email=\u0026sfph_mail="
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5aeea62b-bd6c-4fe2-8c0f-8c9919688e87?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}



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