Vulnerability in Helpfulcrowd Product Reviews

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (38.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-8499: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8499?
CVE-2026-8499 is a medium-severity vulnerability in Helpfulcrowd Product Reviews, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 5.3/10. Published 2026-06-09.
How severe is CVE-2026-8499?
Medium severity. CVSS v3 base score is 5.3 out of 10.