title: Discourse may allow exposure of hidden tags in the subject of notification emails
description: Discourse is an open-source discussion platform. Prior to version 2.8.13 of the `stable` branch and version 2.9.0.beta14 of the `beta` and `tests-passed` branches, unauthorized users may learn of the existence of hidden tags and that they have been applied to topics that they have access to. This issue is patched in version 2.8.13 of the `stable` branch and version 2.9.0.beta14 of the `beta` and `tests-passed` branches. As a workaround, use the `disable_email` site setting to disable all emails to non-staff users.
problem types: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
affected:
{
vendor: discourse
product: discourse
versions:
version: < 2.8.13, status: affected
version: >= 2.9.0.beta0, < 2.9.0.beta14, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: LOW
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: LOW
integrityImpact: NONE
availabilityImpact: NONE
baseScore: 4.3
baseSeverity: MEDIUM
]