CVE-2024-26145Network attack vector

Private-event access via unchecked self-invitation

Published Feb 21, 2024 · Updated Aug 27, 2024

Incorrect authorization in Discourse Calendar allows remote authenticated users to access private events through attendance updates. The invitees controller create action checked only whether the requester could see the event post, then created attendance without verifying can_user_update_attendance. Any signed-in user who can see the post can mark attendance and thereby gain access to a private event.

CVSS severity6.5
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Discourse Calendar allows remote authenticated users to access private events through attendance updates. The invitees controller create action checked only whether the requester could see the event post, then created attendance without verifying can_user_update_attendance. Any signed-in user who can see the post can mark attendance and thereby gain access to a private event.

The record

CVE
CVE-2024-26145
Published
Feb 21, 2024
Updated
Aug 27, 2024
Vendor
Discourse
Product
Discourse Calendar
Classifications
CWE-863
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2024Record 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=>= 2201b254, < dfc4fa15f340189f177a1d1ab2cc94ffed3c1190

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourse Calendarversion=>= 2201b254, < dfc4fa15f340189f177a1d1ab2cc94ffed3c1190

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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