CVE-2022-21684Network attack vector

Unauthenticated forum access via invite auto-login

Published Jan 13, 2022 · Updated Apr 23, 2025

Authentication bypass in Discourse before 2.7.13 and before 2.8.0.beta11 allows remote attackers with emailed invitations to access forums. The invitation acceptance path in InvitesController calls log_on_user for any active invitee without checking guardian.can_access_forum?, creating a session for an unapproved account. Reachability requires must_approve_users and an emailed invitation; the resulting session can read and post as an approved user until logout.

CVSS severity8.8
High
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Discourse before 2.7.13 and before 2.8.0.beta11 allows remote attackers with emailed invitations to access forums. The invitation acceptance path in InvitesController calls log_on_user for any active invitee without checking guardian.can_access_forum?, creating a session for an unapproved account. Reachability requires must_approve_users and an emailed invitation; the resulting session can read and post as an approved user until logout.

The record

CVE
CVE-2022-21684
Published
Jan 13, 2022
Updated
Apr 23, 2025
Vendor
Discourse
Product
Discourse
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.7.13
  2. Affected versionversion=< 2.8.0.beta11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Discourse · Discourseversion=< 2.7.13; version=< 2.8.0.beta11

Published CVSS scores

8.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST National Vulnerability DatabaseAV:N/AC:M/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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