CVE-2026-8868

The Single Mailchimp plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'single-mailchimp' shortcode in all versions up to, and including, 1.4. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (autocomplete, label, placeholder, btn_text, success_msg, error_msg) which are concatenated directly into HTML output by the single_mailchimp() function in shortcodes.php. 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.

CVSS v3 6.4 MEDIUM

6.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.1 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L23
https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L9
https://www.wordfence.com/threat-intel/vulnerabilities/id/070616c9-b6a3-43d9-a82d-5cbcffc39ad9?source=cve

Configurations

No configuration.

History

27 May 2026, 07:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-27 07:16

Updated : 2026-06-17 11:04

NVD link : CVE-2026-8868

Mitre link : CVE-2026-8868

CVE.ORG link : CVE-2026-8868

JSON object : View

Products Affected

No product.

CWE

CWE-79

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

{"id": "CVE-2026-8868", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-8868", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-05-27T10:18:08.564974Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@wordfence.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.4, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 3.1}]}, "affected": [{"source": "security@wordfence.com", "affectedData": [{"vendor": "jonathan-robrecht", "product": "Single Mailchimp", "versions": [{"status": "affected", "version": "0", "versionType": "semver", "lessThanOrEqual": "1.4"}], "defaultStatus": "unaffected"}]}], "published": "2026-05-27T07:16:16.220", "references": [{"url": "https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L23", "source": "security@wordfence.com"}, {"url": "https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L9", "source": "security@wordfence.com"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/070616c9-b6a3-43d9-a82d-5cbcffc39ad9?source=cve", "source": "security@wordfence.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security@wordfence.com", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "The Single Mailchimp plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'single-mailchimp' shortcode in all versions up to, and including, 1.4. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (autocomplete, label, placeholder, btn_text, success_msg, error_msg) which are concatenated directly into HTML output by the single_mailchimp() function in shortcodes.php. 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."}], "lastModified": "2026-06-17T11:04:32.710", "sourceIdentifier": "security@wordfence.com"}