CVE-2026-15158

What it is

The Blocksy Companion plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.1.46 via the save_attachments function. This is due to the Custom Fonts extension registering a wp_check_filetype_and_ext filter that approves any filename containing .woff2 or .ttf as a substring via strpos() rather than validating that those strings appear as the final extension via PATHINFO_EXTENSION — allowing double-extension filenames such as shell.woff2.php to pass MIME validation and be handled as permitted font files. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. This vulnerability is only exploitable when the premium version of the plugin (blocksy-companion-pro) is installed with both the WooCommerce Extra (Advanced Reviews) and Custom Fonts extensions active; the free blocksy-companion plugin does not contain the vulnerable code paths.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

1.1% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-07-08 20:08 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-07-09 10:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-07-09 16:19 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.1% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2026-07-09 10:16 UTC

Last modified

2026-07-09 16:19 UTC

Exploit probability

1.1% · EPSS, next 30 days

Weakness

CWE-434 · Unrestricted file upload

Record status

Deferred

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-15158.md and follow it. Check whether this project is affected by CVE-2026-15158. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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