CVE-2023-40203 | WordPress MailChimp Forms by MailMunch plugin <= 3.1.4 - Broken Access Control

Missing Authorization vulnerability in MailMunch MailChimp Forms by MailMunch allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects MailChimp Forms by MailMunch: from n/a through 3.1.4.

Published: 2024-12-13 Last update: 2026-04-28 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-40203 is rated Low Risk (37.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.39%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2023-40203

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 2025-11-21 0.51% 0.39% -0.13%
2 2025-11-18 0.39% 0.51% +0.13%
3 2025-10-09 0.39%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-40203

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
2.8 1.4 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2023-40203

Affected software / configurations for CVE-2023-40203

Vendor Product Version Raw CPE
mailmunch mailchimp_forms < 3.1.5 cpe:2.3:a:mailmunch:mailchimp_forms:*:*:*:*:*:wordpress:*:*

References for CVE-2023-40203

cvelogic Threat Intelligence