CVE-2022-4939 | WCFM Membership <= 2.10.0 - Unauthenticated Privilege Escalation

THe WCFM Membership plugin for WordPress is vulnerable to privilege escalation in versions up to, and including 2.10.0, due to a missing capability check on the wp_ajax_nopriv_wcfm_ajax_controller AJAX action that controls membership settings. This makes it possible for unauthenticated attackers to modify the membership registration form in a way that allows them to set the role for registration to that of any user including administrators. Once configured, the attacker can then register as an administrator.

Published: 2023-04-05 Last update: 2026-04-08 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-4939 is rated High Risk (77/100): CVSS Critical severity, with high exploitation likelihood (EPSS 20.32%, 96th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +4.38% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-4939

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-14 15.94% 20.32% +4.38%
2 2026-04-13 7.33% 15.94% +8.61%
3 2026-01-30 — 7.33% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-4939

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2022-4939

Affected software / configurations for CVE-2022-4939

Vendor Product Version Raw CPE
wclovers wcfm_membership < 2.10.1 cpe:2.3:a:wclovers:wcfm_membership:*:*:*:*:*:wordpress:*:*

References for CVE-2022-4939

cvelogic Threat Intelligence