Vulnerability · CVE-2026-26973
Discourse is an open source discussion platform.
Published Feb 26, 2026 · corrected/updated Jun 17, 2026 · discourse discourse · evidence confidence medium
Discourse is an open source discussion platform. Versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 have an IDOR (Insecure Direct Object Reference) in . When is enabled, a user belonging to a category moderation group can create or delete their own notes on **any** reviewable in the system, including reviewables in categories they do not moderate. The controller used an unscoped and the guard only checked whether the user could access the review queue in general, not whether they could access the specific reviewable. Only instances with enabled are affected. Staff users (admins/moderators) are not impacted as they already have access to all reviewables. The issue is patched in versions 2025.12.2, 2026.1.1, and 2026.2.0 by scoping the reviewable lookup through . As a workaround, disable the site setting. This removes the attack surface as only staff users will have access to the review queue.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-26973 is a medium public vulnerability record for discourse discourse. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether discourse discourse is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: discourse/discourse; discourse/discourse (2026.2.0). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 4.3. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-639, CWE-863. Sources contributing to this record: cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Feb 26, 2026 · NIST NVD
Detected
Discourse is an open source discussion platform. Versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 have an IDOR (Insecure Direct Object Reference) in . When is enabled, a user belonging to a category moderation group can create or delete their own notes on **any** reviewable in the system, including reviewables in categories they do not moderate. The controller used an unscoped and the guard onl
Jun 17, 2026 · NIST NVD
Updated
Discourse is an open source discussion platform. Versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 have an IDOR (Insecure Direct Object Reference) in . When is enabled, a user belonging to a category moderation group can create or delete their own notes on **any** reviewable in the system, including reviewables in categories they do not moderate. The controller used an unscoped and the guard onl
Affected
- cpe discourse/discourseversion unspecified
- cpe discourse/discourse2026.2.0
Sources
- CVE.orgVulnerability recordCVE-2026-26973
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-26973
Discourse is an open source discussion platform. Versions prior to 2025.12.2, 2026.1.1, and 2026.2.0 have an IDOR (Insecure Direct Object Reference) in . When is enabled, a user belonging to a category moderation grou
nvd.nist.gov