CVE-2026-8787

CVE-2026-8787 is a high-severity vulnerability with a CVSS 3.x base score of 8.8. 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-269.

Key facts

Description

The Firebase Support & Chat Management plugin for WordPress is vulnerable to privilege escalation in all versions up to, and including, 3.1.1. This is due to the `firebase_auth()` function authenticating the request as the WordPress user whose email is supplied in the `user_email` POST parameter without verifying ownership of that email (no Firebase ID token signature/issuer/audience verification). This makes it possible for authenticated attackers, with Subscriber-level access and above, to log in as an arbitrary existing user — including an Administrator — by submitting that user's email address to the `acb_firebase_auth` AJAX action, resulting in full account takeover.

Frequently asked questions

What is CVE-2026-8787?
The Firebase Support & Chat Management plugin for WordPress is vulnerable to privilege escalation in all versions up to, and including, 3.1.1. This is due to the `firebase_auth()` function authenticating the request as the WordPress user whose email is supplied in the `user_email` POST parameter without verifying ownership of that email (no Firebase ID token signature/issuer/audience verification). This makes it possible for authenticated attackers, with Subscriber-level access and above, to log in as an arbitrary existing user — including an Administrator — by submitting that user's email address to the `acb_firebase_auth` AJAX action, resulting in full account takeover.
How severe is CVE-2026-8787?
CVE-2026-8787 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-8787 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-8787?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-8787 have an EU (EUVD) identifier?
Yes. CVE-2026-8787 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32079.
When was CVE-2026-8787 published?
CVE-2026-8787 was published on 2026-05-27 and last updated on 2026-06-17.

References

Other CWE-269 (Improper Privilege Management) vulnerabilities

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