CVE-2021-41140Network attack vector

Reaction metadata disclosure via missing topic authorization

Published Oct 19, 2021 · Updated Aug 4, 2024

Information disclosure in Discourse Reactions before 0.2 allows remote attackers to view reactions on private messages and secure topics. The reactions_given controller query returns reaction records without filtering topics through the requesting user's message and category permissions. A reachable user profile and reactions on restricted content are required; exposed data is limited to reaction metadata.

CVSS severity5.3
Medium
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Discourse Reactions before 0.2 allows remote attackers to view reactions on private messages and secure topics. The reactions_given controller query returns reaction records without filtering topics through the requesting user's message and category permissions. A reachable user profile and reactions on restricted content are required; exposed data is limited to reaction metadata.

The record

CVE
CVE-2021-41140
Published
Oct 19, 2021
Updated
Aug 4, 2024
Vendor
Discourse
Product
Discourse Reactions
Classifications
CWE-200, CWE-668
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=< 0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Discourse · Discourse Reactionsversion=< 0.2

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-668Exposure of Resource to Wrong Sphere

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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