CVE-2026-111311: File Upload RCE (CVSS 8.8)

Description

The DoubleScale | All-in-One CRM – Sales, Multi-Channel Marketing, Newsletter, Booking, Helpdesk, Automation, MCP & More plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.5.1 via the store_upload function. This is due to a fail-open extension allow-list in extension_is_allowed() that returns true when wp_check_filetype() yields an empty type for unrecognized extensions such as .php, combined with magic-byte-only MIME detection and no capability check beyond is_user_logged_in(). This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. Exploitation requires the Helpdesk module to be enabled, as the vulnerable REST endpoint is only registered when that module is active.

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CVSS v3.1 Score

8.8

HIGH

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

EPSS — Exploit Prediction

0.0051

Probability of exploitation

0.44%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-434 Unrestricted Upload

References

Other References

https://plugins.trac.wordpress.org/browser/doublescale/tags/1.4.6/includes/Core/Services/AttachmentService.php#L112 https://plugins.trac.wordpress.org/browser/doublescale/tags/1.4.6/includes/Core/Services/AttachmentService.php#L446 https://plugins.trac.wordpress.org/browser/doublescale/tags/1.4.6/includes/Modules/Support/Rest/Controllers/RestPortalController.php#L574 https://plugins.trac.wordpress.org/browser/doublescale/tags/1.4.6/includes/Modules/Support/Rest/Controllers/RestPortalController.php#L622 https://www.wordfence.com/threat-intel/vulnerabilities/id/0feed03e-fedf-4443-94e0-fbb2c8baba71?source=cve

Frequently Asked Questions

What is CVE-2026-111311? +

The DoubleScale | All-in-One CRM – Sales, Multi-Channel Marketing, Newsletter, Booking, Helpdesk, Automation, MCP & More plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.5.1 via the store_upload function. This is due to a fail-open extension allow-list in extension_is_allowed() that returns true when wp_check_filetype() yields an empty type for unrecognized extensions such as .php, combined with magic-byte-only MIME detection and no capability check beyond is_user_logged_in(). This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. Exploitation requires the Helpdesk module to be enabled, as the vulnerable REST endpoint is only registered when that module is active. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-111311? +

CVE-2026-111311 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0051, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-111311? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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