CVE-2022-39356: Discourse user account takeover via email and invite link

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-11-02 · updated 2026-06-17
Weakness: CWE-285

Description

Discourse is a platform for community discussion. Users who receive an invitation link that is not scoped to a single email address can enter any non-admin user's email and gain access to their account when accepting the invitation. All users should upgrade to the latest version. A workaround is temporarily disabling invitations with `SiteSetting.max_invites_per_day = 0` or scope them to individual email addresses.

Affected products

discourse: before 2.8.10; 2.9.0-beta1, 2.9.0-beta10, 2.9.0-beta2, 2.9.0-beta3, 2.9.0-beta4, 2.9.0-beta5 (+4) — fixed in 2.8.10

How to fix

Upgrade to a fixed version: discourse 2.8.10. Check the vendor advisory for mitigations.

References

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