CVE-2026-18978 (GCVE-0-2026-18978)

Vulnerability from cvelistv5 – Published: 2026-08-28 03:39 – Updated: 2026-08-28 03:39
VLAI
Title
LiteSpeed Cache <= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Summary
The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 7.8.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A comment payload crafted exclusively from decimal numeric character references (e.g. &#34;, &#60;, &#62;) placed inside an allowed element such as &lt;code&gt; bypasses WordPress's wp_kses sanitization, as kses does not treat a data-settings="..." substring within text content as an HTML attribute, allowing the malicious payload to reach the vulnerable function. For this to be exploitable, the site must allow users with previously approved comments to write new comments, and the require_name_email setting must be disabled.
Severity
7.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version CPE status
litespeedtech LiteSpeed Cache Affected: 0 , ≤ 7.8.1 (semver)
guessed Create a notification for this product.
Credits
Jack Taylor
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "LiteSpeed Cache",
          "vendor": "litespeedtech",
          "versions": [
            {
              "lessThanOrEqual": "7.8.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
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          "type": "finder",
          "value": "Jack Taylor"
        }
      ],
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          "value": "The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 7.8.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A comment payload crafted exclusively from decimal numeric character references (e.g. \u0026#34;, \u0026#60;, \u0026#62;) placed inside an allowed element such as \u0026lt;code\u0026gt; bypasses WordPress\u0027s wp_kses sanitization, as kses does not treat a data-settings=\"...\" substring within text content as an HTML attribute, allowing the malicious payload to reach the vulnerable function. For this to be exploitable, the site must allow users with previously approved comments to write new comments, and the require_name_email setting must be disabled."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.2,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79 Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T03:39:34.235Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/0b045f3d-8412-4e35-b369-2b485639274d?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1405"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1358"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1317"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L777"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset/3635849/litespeed-cache/trunk/src/media.cls.php"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset?old_path=%2Flitespeed-cache/tags/7.8.1\u0026new_path=%2Flitespeed-cache/tags/7.9"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-08-05T16:50:13.000Z",
          "value": "Vendor Notified"
        },
        {
          "lang": "en",
          "time": "2026-08-27T15:19:36.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "LiteSpeed Cache \u003c= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment Content"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "cveId": "CVE-2026-18978",
    "datePublished": "2026-08-28T03:39:34.235Z",
    "dateReserved": "2026-08-05T16:34:59.611Z",
    "dateUpdated": "2026-08-28T03:39:34.235Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-18978\",\"sourceIdentifier\":\"security@wordfence.com\",\"published\":\"2026-08-28T05:16:41.927\",\"lastModified\":\"2026-08-28T05:16:41.927\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 7.8.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A comment payload crafted exclusively from decimal numeric character references (e.g. \u0026#34;, \u0026#60;, \u0026#62;) placed inside an allowed element such as \u0026lt;code\u0026gt; bypasses WordPress\u0027s wp_kses sanitization, as kses does not treat a data-settings=\\\"...\\\" substring within text content as an HTML attribute, allowing the malicious payload to reach the vulnerable function. For this to be exploitable, the site must allow users with previously approved comments to write new comments, and the require_name_email setting must be disabled.\"}],\"affected\":[{\"source\":\"security@wordfence.com\",\"affectedData\":[{\"vendor\":\"litespeedtech\",\"product\":\"LiteSpeed Cache\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"0\",\"lessThanOrEqual\":\"7.8.1\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security@wordfence.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N\",\"baseScore\":7.2,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":2.7}]},\"weaknesses\":[{\"source\":\"security@wordfence.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"references\":[{\"url\":\"https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1317\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1358\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1405\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L777\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/changeset/3635849/litespeed-cache/trunk/src/media.cls.php\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://plugins.trac.wordpress.org/changeset?old_path=%2Flitespeed-cache/tags/7.8.1\u0026new_path=%2Flitespeed-cache/tags/7.9\",\"source\":\"security@wordfence.com\"},{\"url\":\"https://www.wordfence.com/threat-intel/vulnerabilities/id/0b045f3d-8412-4e35-b369-2b485639274d?source=cve\",\"source\":\"security@wordfence.com\"}]}}"
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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