Vulnerability-Lookup

GHSA-855Q-XM3J-J7H8

Vulnerability from github – Published: 2026-06-02 03:31 – Updated: 2026-06-02 03:31

Details

The Simple Custom Login Page plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the color settings fields (Page Background, Form Background, Text Color, Link Color) in versions up to and including 1.0.3. This is due to insufficient input sanitization of the color option values (they were registered with register_setting() and stored via the Settings API/update_option() with no sanitize_callback) combined with the values being output into a block on wp-login.php using esc_attr(), which is incorrect for a CSS context (it does not escape ;, {, }, / or *). This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary CSS rules into the login page that are rendered for all unauthenticated visitors, enabling UI-redress and credential-phishing attacks.

Severity

4.4 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-10100"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-02T03:16:15Z",
    "severity": "MODERATE"
  },
  "details": "The Simple Custom Login Page plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the color settings fields (Page Background, Form Background, Text Color, Link Color) in versions up to and including 1.0.3. This is due to insufficient input sanitization of the color option values (they were registered with register_setting() and stored via the Settings API/update_option() with no sanitize_callback) combined with the values being output into a \u003cstyle\u003e block on wp-login.php using esc_attr(), which is incorrect for a CSS context (it does not escape ;, {, }, / or *). This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary CSS rules into the login page that are rendered for all unauthenticated visitors, enabling UI-redress and credential-phishing attacks.",
  "id": "GHSA-855q-xm3j-j7h8",
  "modified": "2026-06-02T03:31:25Z",
  "published": "2026-06-02T03:31:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-10100"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/admin/class-simple-custom-login-page-admin.php#L206"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/includes/class-simple-custom-login-page.php#L248"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/96d03984-623a-44c7-a46f-e1aabbc566d5?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-10100 (GCVE-0-2026-10100)

Vulnerability from cvelistv5 – Published: 2026-06-02 01:28 – Updated: 2026-06-02 10:48

Title

Simple Custom Login Page <= 1.0.3 - Authenticated (Admin+) Stored Cross-Site Scripting

Summary

The Simple Custom Login Page plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the color settings fields (Page Background, Form Background, Text Color, Link Color) in versions up to and including 1.0.3. This is due to insufficient input sanitization of the color option values (they were registered with register_setting() and stored via the Settings API/update_option() with no sanitize_callback) combined with the values being output into a <style> block on wp-login.php using esc_attr(), which is incorrect for a CSS context (it does not escape ;, {, }, / or *). This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary CSS rules into the login page that are rendered for all unauthenticated visitors, enabling UI-redress and credential-phishing attacks.

Severity

4.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

Wordfence

References

3 references

URL	Tags
https://www.wordfence.com/threat-intel/vulnerabil…
https://plugins.trac.wordpress.org/browser/simple…
https://plugins.trac.wordpress.org/browser/simple…

Impacted products

1 product

Vendor	Product	Version
pattihis	Simple Custom Login Page	Affected: 0 , ≤ 1.0.3 (semver)

Credits

Nguyen Duong

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-10100",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-02T10:39:35.212951Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
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        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-02T10:48:01.147Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Simple Custom Login Page",
          "vendor": "pattihis",
          "versions": [
            {
              "lessThanOrEqual": "1.0.3",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Nguyen Duong"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The Simple Custom Login Page plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the color settings fields (Page Background, Form Background, Text Color, Link Color) in versions up to and including 1.0.3. This is due to insufficient input sanitization of the color option values (they were registered with register_setting() and stored via the Settings API/update_option() with no sanitize_callback) combined with the values being output into a \u003cstyle\u003e block on wp-login.php using esc_attr(), which is incorrect for a CSS context (it does not escape ;, {, }, / or *). This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary CSS rules into the login page that are rendered for all unauthenticated visitors, enabling UI-redress and credential-phishing attacks."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 4.4,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
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      ],
      "problemTypes": [
        {
          "descriptions": [
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              "cweId": "CWE-79",
              "description": "CWE-79 Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
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              "type": "CWE"
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      "providerMetadata": {
        "dateUpdated": "2026-06-02T01:28:04.579Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
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        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/96d03984-623a-44c7-a46f-e1aabbc566d5?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/includes/class-simple-custom-login-page.php#L248"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/admin/class-simple-custom-login-page-admin.php#L206"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-06-01T13:15:11.000Z",
          "value": "Vendor Notified"
        },
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          "lang": "en",
          "time": "2026-06-01T13:00:11.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "Simple Custom Login Page \u003c= 1.0.3 - Authenticated (Admin+) Stored Cross-Site Scripting"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
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    "datePublished": "2026-06-02T01:28:04.579Z",
    "dateReserved": "2026-05-29T15:07:45.775Z",
    "dateUpdated": "2026-06-02T10:48:01.147Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-855Q-XM3J-J7H8

CVE-2026-10100 (GCVE-0-2026-10100)

Tags

Sightings

Nomenclature