CVE-2026-5127
CVE-2026-5127 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-502.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- EPSS exploit prediction: 1% (57th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-28538
- Weakness: CWE-502
- Published:
- Last modified:
Description
The User Frontend: AI Powered Frontend Posting, User Directory, Profile, Membership & User Registration plugin for WordPress is vulnerable to Deserialization of Untrusted Data in versions up to, and including, 4.3.1 This is due to insufficient input validation and type checking on the wpuf_files parameter during form submission, combined with unconditional deserialization via maybe_unserialize() when displaying post content. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary PHP objects, which can be leveraged to execute arbitrary code, delete arbitrary files, or perform other malicious actions if a POP chain is present on the target system.
Frequently asked questions
- What is CVE-2026-5127?
- The User Frontend: AI Powered Frontend Posting, User Directory, Profile, Membership & User Registration plugin for WordPress is vulnerable to Deserialization of Untrusted Data in versions up to, and including, 4.3.1 This is due to insufficient input validation and type checking on the wpuf_files parameter during form submission, combined with unconditional deserialization via maybe_unserialize() when displaying post content. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary PHP objects, which can be leveraged to execute arbitrary code, delete arbitrary files, or perform other malicious actions if a POP chain is present on the target system.
- How severe is CVE-2026-5127?
- CVE-2026-5127 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-2026-5127 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-5127?
- 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-2026-5127 have an EU (EUVD) identifier?
- Yes. CVE-2026-5127 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28538.
- When was CVE-2026-5127 published?
- CVE-2026-5127 was published on 2026-05-08 and last updated on 2026-06-17.
References
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Ajax/Frontend_Form_Ajax.php#L35
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Ajax/Frontend_Form_Ajax.php#L36
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Traits/FieldableTrait.php#L429
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Traits/FieldableTrait.php#L502
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Traits/FieldableTrait.php#L679
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/includes/Traits/FieldableTrait.php#L704
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/wpuf-functions.php#L1103
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/tags/4.2.10/wpuf-functions.php#L959
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Ajax/Frontend_Form_Ajax.php#L35
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Ajax/Frontend_Form_Ajax.php#L36
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Traits/FieldableTrait.php#L429
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Traits/FieldableTrait.php#L502
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Traits/FieldableTrait.php#L679
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/includes/Traits/FieldableTrait.php#L704
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/wpuf-functions.php#L1103
- https://plugins.trac.wordpress.org/browser/wp-user-frontend/trunk/wpuf-functions.php#L959
- https://plugins.trac.wordpress.org/changeset/3514258/wp-user-frontend/trunk/includes/Traits/FieldableTrait.php
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fwp-user-frontend/tags/4.3.1&new_path=%2Fwp-user-frontend/tags/4.3.2
- https://www.wordfence.com/threat-intel/vulnerabilities/id/2b5d27cc-c6eb-4c5c-8ee1-30483b91c6fd?source=cve
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