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Vulnerabilities

Vulnerability · CVE-2026-26973

Discourse is an open source discussion platform.

Published Feb 26, 2026 · catalog updated Jun 17, 2026 · Discourse is an open

Check if you run it

No confirmed exploitation is on record for CVE-2026-26973. EPSS is 0.27%. Act only if a listed version of Discourse is an open is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Discourse is an open).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium4.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.27%
Remediation
Advisory link
Affected products
cpe discourse/discourse

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe discourse/discourse2026.2.0

How to fix CVE-2026-26973

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-26973. EPSS is 0.27%. Act only if a listed version of Discourse is an open is installed.

Which versions are affected?

Compare what you have installed with 2026.2.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-639: Authorization Bypass Through User-Controlled Key; CWE-863: Incorrect Authorization. EPSS 0.27%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. 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

  2. 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

Sources

  • CVE.orgVulnerability recordCVE-2026-26973

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-26973

    30-day exploitation probability 0.3%

    first.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

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.