CVE-2026-77871 (GCVE-0-2026-77871)
Vulnerability from cvelistv5
Published
2026-10-28 06:45
Modified
2026-10-29 01:41
Severity ?
6.4 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Summary
The Post Snippets – Custom WordPress Code Snippets Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 4.2.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Entity-encoded payloads such as <script>...</script> survive WordPress's wp_kses_post on-save sanitization because kses does not decode HTML entities, and are only converted back into executable HTML tags at render time by the plugin's own shortcode filter. This requires snippet shortcodes to be enabled.
References
Impacted products
Vendor Product Version
saadiqbal Post Snippets – Custom WordPress Code Snippets Customizer Version: 0   ≤ 4.2.4
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-77871",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-29T01:33:15.822523Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-29T01:41:51.567Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Post Snippets \u2013 Custom WordPress Code Snippets Customizer",
          "vendor": "saadiqbal",
          "versions": [
            {
              "lessThanOrEqual": "4.2.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Wordfence PRISM"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Post Snippets \u2013 Custom WordPress Code Snippets Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 4.2.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Entity-encoded payloads such as \u0026lt;script\u0026gt;...\u0026lt;/script\u0026gt; survive WordPress\u0027s wp_kses_post on-save sanitization because kses does not decode HTML entities, and are only converted back into executable HTML tags at render time by the plugin\u0027s own shortcode filter. This requires snippet shortcodes to be enabled."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 6.4,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/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": "2026-10-28T06:45:18.731Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/a46c37f4-245d-423f-bdad-296fdf377ecc?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L183"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L183"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L140"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L70"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L29"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L140"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L70"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L29"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset/3759640/post-snippets/trunk/src/PostSnippets/Shortcode.php"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-08-21T15:11:01.000Z",
          "value": "Vendor Notified"
        },
        {
          "lang": "en",
          "time": "2026-10-27T17:42:22.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "Post Snippets \u003c= 4.2.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "cveId": "CVE-2026-77871",
    "datePublished": "2026-10-28T06:45:18.731Z",
    "dateReserved": "2026-08-21T14:55:54.492Z",
    "dateUpdated": "2026-10-29T01:41:51.567Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Post Snippets \u003c= 4.2.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes\", \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Wordfence PRISM\"}], \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 6.4, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N\"}}], \"affected\": [{\"vendor\": \"saadiqbal\", \"product\": \"Post Snippets \\u2013 Custom WordPress Code Snippets Customizer\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"4.2.4\"}], \"defaultStatus\": \"unaffected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-08-21T15:11:01.000Z\", \"value\": \"Vendor Notified\"}, {\"lang\": \"en\", \"time\": \"2026-10-27T17:42:22.000Z\", \"value\": \"Disclosed\"}], \"references\": [{\"url\": \"https://www.wordfence.com/threat-intel/vulnerabilities/id/a46c37f4-245d-423f-bdad-296fdf377ecc?source=cve\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L183\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L183\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L140\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L70\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.4/src/PostSnippets/Shortcode.php#L29\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L140\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L70\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/post-snippets/tags/4.2.3/src/PostSnippets/Shortcode.php#L29\"}, {\"url\": \"https://plugins.trac.wordpress.org/changeset/3759640/post-snippets/trunk/src/PostSnippets/Shortcode.php\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The Post Snippets \\u2013 Custom WordPress Code Snippets Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 4.2.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Entity-encoded payloads such as \u0026lt;script\u0026gt;...\u0026lt;/script\u0026gt; survive WordPress\u0027s wp_kses_post on-save sanitization because kses does not decode HTML entities, and are only converted back into executable HTML tags at render time by the plugin\u0027s own shortcode filter. This requires snippet shortcodes to be enabled.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-79\", \"description\": \"CWE-79 Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"shortName\": \"Wordfence\", \"dateUpdated\": \"2026-10-28T06:45:18.731Z\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-77871\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-29T01:33:15.822523Z\"}}}], \"providerMetadata\": {\"shortName\": \"CISA-ADP\", \"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"dateUpdated\": \"2026-10-29T01:38:11.859Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-77871\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-28T06:45:18.731Z\", \"dateReserved\": \"2026-08-21T14:55:54.492Z\", \"assignerOrgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"datePublished\": \"2026-10-28T06:45:18.731Z\", \"assignerShortName\": \"Wordfence\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.