CVE-2026-4373

JetFormBuilder <= 3.5.6.2 - Unauthenticated Arbitrary File Read via Media Field

2026-03-20 18:28

Strategic Overview

Status: Patched in 3.5.6.3
Affected Plugin: JetFormBuilder — Dynamic Blocks Form Builder
Affected Version: <= 3.5.6.2
CVSS: 7.5High
Weakness type: CWE-36 · Absolute Path Traversal
CVE: CVE-2026-4373

View all JetFormBuilder — Dynamic Blocks Form Builder vulnerabilities

At a glance

CVE-2026-4373 is a high-severity Absolute Path Traversal vulnerability in the JetFormBuilder WordPress plugin, affecting versions <= 3.5.6.2. It carries a CVSS score of 7.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 3.5.6.3; sites on affected versions should update now. Disclosed March 2026, reported by daroo.

Vulnerability Overview

The JetFormBuilder plugin for WordPress is vulnerable to arbitrary file read via path traversal in all versions up to, and including, 3.5.6.2. This is due to the 'Uploaded_File::set_from_array' method accepting user-supplied file paths from the Media Field preset JSON payload without validating that the path belongs to the WordPress uploads directory. Combined with an insufficient same-file check in 'File_Tools::is_same_file' that only compares basenames, this makes it possible for unauthenticated attackers to exfiltrate arbitrary local files as email attachments by submitting a crafted form request when the form is configured with a Media Field and a Send Email action with file attachment.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-36: Absolute Path Traversal

The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as /abs/path that can resolve to a location that is outside of that directory.

Remediation

Update to version 3.5.6.3, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: JetFormBuilder 3.5.6.3 closes this, and updating the plugin is the step that ends it.

Firewall
Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-4373 https://www.wordfence.com/threat-intel/vulnerabilities/id/1801fd3e-d56f-4540-9700-9e9de8b465e1 https://nvd.nist.gov/vuln/detail/CVE-2026-4373

Related records

Other vulnerabilities in JetFormBuilder — Dynamic Blocks Form Builder

CVSS Vector

7.5

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityNone

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