Restricted tag-group name disclosure via missing visibility filtering
Published Jun 12, 2026 · Updated Jun 12, 2026
Information disclosure in Discourse allows remote attackers to read restricted tag-group names through the unauthenticated tag-info endpoint. DetailedTagSerializer#tag_group_names returns every group for a tag without checking whether the requester can view each group. Exposure requires tags_listed_by_group to be enabled; anonymous access then reveals names tied to restricted user groups or hidden categories, but not their contents.
Summary
What happened
Information disclosure in Discourse allows remote attackers to read restricted tag-group names through the unauthenticated tag-info endpoint. DetailedTagSerializer#tag_group_names returns every group for a tag without checking whether the requester can view each group. Exposure requires tags_listed_by_group to be enabled; anonymous access then reveals names tied to restricted user groups or hidden categories, but not their contents.
The record
- CVE
- CVE-2026-47264
- Published
- Jun 12, 2026
- Updated
- Jun 12, 2026
- Vendor
- Discourse
- Product
- Discourse
- Classifications
- CWE-200
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 12, 2026CVE publishedPublication date reported by the CVE source.
- Jun 12, 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.
- Affected versionversion=>= 2026.1.0-latest, < 2026.1.4
- Affected versionversion=>= 2026.3.0-latest, < 2026.3.1
- Affected versionversion=>= 2026.4.0-latest, < 2026.4.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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