CVE-2026-1303Network attack vector

Campaign disruption via unchecked app disconnection

Published Feb 14, 2026 · Updated Feb 14, 2026

Missing authorization in MailChimp Campaigns 3.2.4 and earlier allows remote authenticated users to disconnect its MailChimp app. The AJAX handler mailchimp_campaigns_manager_disconnect_app performs the disconnection without checking the caller's WordPress capabilities. Subscriber-level access reaches the handler, interrupting campaign synchronization and dependent marketing integrations.

CVSS severity5.3
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in MailChimp Campaigns 3.2.4 and earlier allows remote authenticated users to disconnect its MailChimp app. The AJAX handler mailchimp_campaigns_manager_disconnect_app performs the disconnection without checking the caller's WordPress capabilities. Subscriber-level access reaches the handler, interrupting campaign synchronization and dependent marketing integrations.

The record

CVE
CVE-2026-1303
Published
Feb 14, 2026
Updated
Feb 14, 2026
Vendor
Matthieu Scarset
Product
MailChimp Campaigns
Classifications
CWE-862, T1489
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <=3.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Matthieu Scarset · MailChimp Campaignsversion=* <=3.2.4

Published CVSS scores

5.3WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1489Service Stop

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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