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TI-2026-75351 Aliases CVE-2026-57447

Discourse Doc Categories leaks private topic titles in index refresh

Priority LOW 19CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-200.

Summary

The Discourse Doc Categories plugin before commit b15d4de02ad29d7c9525346afee51fef4a2c605a does not enforce viewer authorization when its doc category index refresh resolves linked titles. This exposes the titles of private messages and restricted category topics (CWE-200). A user with low privileges who can edit the index topic over the network can learn titles they are not authorized to view, though the advisory does not establish access to topic contents.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Discourse Doc Categories is a plugin for organizing Discourse topics as documentation. Prior to the verified source fix, the doc category index refresh resolves linked titles for private messages or restricted category topics without enforcing the viewer's authorization. A user who can edit the index topic can use this behavior to learn titles that the user is not authorized to view, although the advisory does not establish access to topic contents. This vulnerability is addressed by commit b15d4de02ad29d7c9525346afee51fef4a2c605a.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00183 7th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
discoursediscourse-doc-categories< b15d4de02ad29d7c9525346afee51fef4a2c605a—No fix listedCNA
  • discourse-doc-categories Vendordiscourse Affected < b15d4de02ad29d7c9525346afee51fef4a2c605a Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for discourse-doc-categories. The advisory states the issue is addressed by commit b15d4de02ad29d7c9525346afee51fef4a2c605a.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-57447
  2. 2026-10-16 CISA SSVC decision points changed

References

Other 2

  • TI-2022-22806 Discourse BBCode plugin vulnerable to arbitrary CSS injection CVSS 3.1CRITICAL 9.8
  • TI-2021-19656 Denial of Service in discourse CVSS 3.1MEDIUM 6.8
  • TI-2024-36150 Potential Backup file leaked via Nginx in Discourse CVSS 3.1HIGH 7.5
  • TI-2021-18002 RCE via malicious SNS subscription payload CVSS 3.1CRITICAL 10.0
  • TI-2026-24651 Discourse: Open redirect via `sso_destination_url` cookie in `enter` CVSS 4.0MEDIUM 5.1
  • TI-2022-18730 Discourse Patreon vulnerable to improper validation of email during Patreon authentication CVSS 3.1CRITICAL 9.8
See all 328 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences