CVE-2026-8499

CVE-2026-8499 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-843.

Key facts

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.

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.
How severe is CVE-2026-8499?
CVE-2026-8499 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-8499 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-8499?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-8499 have an EU (EUVD) identifier?
Yes. CVE-2026-8499 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35302.
When was CVE-2026-8499 published?
CVE-2026-8499 was published on 2026-06-09 and last updated on 2026-06-17.

References

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