CVE-2026-8499

Description

The Helpfulcrowd Product Reviews plugin for WordPress is vulnerable to Authorization Bypass via PHP Type Juggling in versions up to, and including, 1.2.9. This is due to the `helpfulcrowd_validate_token()` function using a loose comparison operator (`!=`) instead of a strict comparison (`!==`) when validating the `token` parameter, while the corresponding REST route `/wp-json/helpfulcrowd/v1/update-settings` is registered with a `permission_callback` of `__return_true`, making it reachable by unauthenticated users; submitting a JSON boolean `true` as the `token` value causes PHP's loose comparison to evaluate as equal to the non-empty base64-encoded secret string, bypassing the check entirely. This makes it possible for unauthenticated attackers to invoke `helpfulcrowd_settings_endpoint()` and write arbitrary attacker-controlled key-value pairs directly into the `helpfulcrowd_options` WordPress database option via `update_option()` without any sanitization or allowlist filtering, enabling full unauthenticated modification of the plugin's stored configuration.

Is your site exposed to CVE-2026-8499?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.19%

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-843 CWE-843

References

Other References

https://plugins.trac.wordpress.org/browser/helpfulcrowd-product-reviews/tags/1.2.9/includes/HelpfulcrowdCustomEndpoints.php#L13 https://plugins.trac.wordpress.org/browser/helpfulcrowd-product-reviews/tags/1.2.9/includes/HelpfulcrowdCustomEndpoints.php#L71 https://plugins.trac.wordpress.org/browser/helpfulcrowd-product-reviews/tags/1.2.9/includes/core.php#L122 https://www.wordfence.com/threat-intel/vulnerabilities/id/26f34aa0-8584-4156-b084-d34a0ab0a997?source=cve

Frequently Asked Questions

What is CVE-2026-8499? +

The Helpfulcrowd Product Reviews plugin for WordPress is vulnerable to Authorization Bypass via PHP Type Juggling in versions up to, and including, 1.2.9. This is due to the `helpfulcrowd_validate_token()` function using a loose comparison operator (`!=`) instead of a strict comparison (`!==`) when validating the `token` parameter, while the corresponding REST route `/wp-json/helpfulcrowd/v1/update-settings` is registered with a `permission_callback` of `__return_true`, making it reachable by unauthenticated users; submitting a JSON boolean `true` as the `token` value causes PHP's loose comparison to evaluate as equal to the non-empty base64-encoded secret string, bypassing the check entirely. This makes it possible for unauthenticated attackers to invoke `helpfulcrowd_settings_endpoint()` and write arbitrary attacker-controlled key-value pairs directly into the `helpfulcrowd_options` WordPress database option via `update_option()` without any sanitization or allowlist filtering, enabling full unauthenticated modification of the plugin's stored configuration. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-8499? +

CVE-2026-8499 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-8499? +

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.

Related Vulnerabilities

CVE-2026-8358

LibreOffice Calc can import tracked changes from a spreadsheet document. A heap buffer overflow existed when a document reused the …

CVE-2026-6210

A type confusion vulnerability in Qt SVG allows an attacker to cause an application crash via a crafted SVG image. …

CVE-2026-6047

LibreOffice can import documents in the OOXML format (DOCX). A heap buffer overflow existed when replaying deferred parser events for …

CVE-2024-5436 9.8

Type confusion in Snapchat LensCore could lead to denial of service or arbitrary code execution prior to version 12.88. We …

CVE-2024-20078 9.8

In venc, there is a possible out of bounds write due to type confusion. This could lead to local escalation …

CVE-2025-22435 9.8

In avdt_msg_ind of avdt_msg.cc, there is a possible memory corruption due to type confusion. This could lead to paired device …