VulnerabilityPublished 6 Nov 2026

CVE-2026-27356: MC4WP (WordPress plugin) · Missing Authorization

Affects MC4WP (WordPress plugin)Source CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 4.15.0 when convenient.

Data as of 6 Nov 2026, 22:51 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (Patchstack)	CVSS 3.1	5.3

Patch: Available – fixed in 4.15.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade MC4WP (WordPress plugin) to 4.15.0.

Affected software

Product	Affected	Fixed in
MC4WPmailchimp-for-wp	Affected <4.15.0	Fixed in 4.15.0

AI-suggested

Upgrade the ibericode MC4WP plugin to version 4.15.0 or later, where this missing authorization vulnerability has been fixed. No other mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-27356 is a missing authorization vulnerability in the ibericode MC4WP (Mailchimp for WordPress) plugin. It affects versions from initial releases up to 4.14.1, allowing attackers to exploit incorrectly configured access control security levels. The issue is fixed in version 4.15.0.

Impact

The vulnerability allows unauthorized users to bypass access control restrictions, potentially leading to unauthorized modification of data within the affected plugin. There is no impact on confidentiality or availability reported. The overall severity is medium based on the CVSS score of 5.3.

Summary

This vulnerability in ibericode MC4WP arises from missing authorization checks, enabling unauthorized users to perform actions that should be restricted. The flaw affects all versions prior to 4.15.0. The vulnerability has a CVSS 3.1 base score of 5.3, indicating a medium severity level, with an impact primarily on integrity due to the ability to modify data without authorization. There is no known exploitation in the wild. The vendor has released version 4.15.0 which addresses this issue.

References

patchstack.com/database/wordpress/plugin/mailchimp-for-wp/vulnerability/wordpress-mc4wp-plugin-4-14-1-broken-access-control-vulnerability?_s_id=cve (opens in a new tab)

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Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 22:51 UTC

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