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TI-2026-75551 Aliases CVE-2026-92798GHSA-fc28-r9m2-c784

Arbitrary shortcode execution in User Registration & Membership

Priority LOW 37CWE-94Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-94.

Summary

The User Registration & Membership plugin for WordPress is affected from 0 through 5.2.8. Its referrer_url smart tag passes the HTTP Referer header through sanitize_text_field(), which does not remove shortcode delimiters, so the value is later run as a shortcode (CWE-94). An attacker with low privileges, such as a Subscriber account, can execute arbitrary registered shortcodes on restricted pages whose message uses the {{referrer_url}} smart tag.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

The User Registration & Membership plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions up to, and including, 5.2.8 This is due to insufficient input sanitization in the 'referrer_url' branch of UR_Smart_Tags::process(), where the attacker-controlled HTTP_REFERER header is only passed through sanitize_text_field() — which does not strip WordPress shortcode delimiters — before being substituted into a Content Restriction message that is subsequently executed via apply_shortcodes()/do_shortcode(). This makes it possible for unauthenticated attackers to execute arbitrary registered shortcodes on any restricted page whose message uses the supported {{referrer_url}} smart tag.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00369 30th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
wpeverestUser Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builderup to 5.2.8—No fix listedCNA
  • User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder Vendorwpeverest Affected up to 5.2.8 Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for User Registration & Membership.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Timeline

  1. 2026-10-18 Threatist record created from CVE-2026-92798
  2. 2026-10-18 Alias added: GHSA-fc28-r9m2-c784

References

Other 6

  • TI-2025-00958 Everest Forms <= 3.0.9.4 - Unauthenticated Arbitrary File Upload, Read, and Deletion CVSS 3.1CRITICAL 9.8
  • TI-2026-02850 Everest Forms Pro <= 1.9.12 - Unauthenticated Remote Code Execution via Calculation Field CVSS 3.1CRITICAL 9.8
  • TI-2026-01188 User Registration & Membership <= 5.1.2 - Unauthenticated Privilege Escalation via Membership Registration CVSS 3.1CRITICAL 9.8
  • TI-2025-02262 User Registration & Membership < 4.1.3 - Authentication Bypass CVSS 3.1HIGH 8.1
  • TI-2025-02232 User Registration & Membership < 4.1.2- Unauthenticated Privilege Escalation CVSS 3.1HIGH 8.1
  • TI-2022-03588 User Registration < 2.2.4.1 - Subscriber+ Arbitrary File Upload CVSS 3.1HIGH 7.5
See all 80 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences