What’s Vulnerable › Vulnerabilities

CVE-2026-84302: Discourse: Non-participant moderators can read, edit, and delete PM content through Discourse AI reviewables

• Severity: medium (CVSS 4.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-24 · updated 2026-09-24
• Weakness: CWE-862

Description

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did not restrict private-message reviewables to the audience permitted to access the underlying private-message topic, allowing the moderator to read otherwise confidential content. Depending on the available reviewable action, the moderator could also modify the private message by closing its topic or deleting a post. Exploitation requires an authenticated moderator account and a pre-existing Discourse AI reviewable associated with a private message. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

Affected products

• discourse: before 2026.7.0; from 2026.6.0-latest, < 2026.6.1; from 2026.5.0-latest, < 2026.5.2; from 2026.1.0-latest, < 2026.1.6

References

• https://github.com/discourse/discourse/commit/1566d04524c01472375944bbf7b198dd09a99427
• https://github.com/discourse/discourse/commit/23488b72a200228e805c4e6d970fbad216d328c5
• https://github.com/discourse/discourse/commit/38d10c0e5d1b76540d2860455e0290f8e975c9fd
• https://github.com/discourse/discourse/commit/b323702d87cd82c327c116d9566477f3c4f9635f
• https://github.com/discourse/discourse/pull/42091
• https://github.com/discourse/discourse/security/advisories/GHSA-3rx9-fqgh-wfpc

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