CVE-2026-18436

Name of the Vulnerable Software and Affected Versions MailPress versions prior to 1.5.1

Description The MailPress plugin for WordPress allows unauthorized access through the campaign revision-restore REST endpoint 'POST /wp-json/mailpress/v1/campaign//restore-revision/'. The issue occurs because the route was registered without a permissionCallback, which enables the restoreRevision() function to process unauthenticated requests. This allows an attacker to overwrite the content html variable of a campaign by restoring any previous revision, effectively modifying the campaign content.

Recommendations Update the plugin to a version later than 1.5.0. As a temporary workaround, restrict access to the 'POST /wp-json/mailpress/v1/campaign//restore-revision/' endpoint to prevent unauthorized modification of campaign content.