CVE-2021-43792Network attack vector

Restricted-tag disclosure via stale notification subscriptions

Published Dec 1, 2021 · Updated Aug 4, 2024

Information exposure in Discourse stable before 2.7.11 allows remote authenticated users to receive restricted-tag notifications. The tag_watchers and notify_post_users queries select persistent tag subscriptions without rechecking current tag-group membership. Exposure requires tracking a restricted tag before losing access; beta and tests-passed before 2.8.0.beta9 are also affected.

CVSS severity4.3
Medium
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

Information exposure in Discourse stable before 2.7.11 allows remote authenticated users to receive restricted-tag notifications. The tag_watchers and notify_post_users queries select persistent tag subscriptions without rechecking current tag-group membership. Exposure requires tracking a restricted tag before losing access; beta and tests-passed before 2.8.0.beta9 are also affected.

The record

CVE
CVE-2021-43792
Published
Dec 1, 2021
Updated
Aug 4, 2024
Vendor
Discourse
Product
Discourse
Classifications
CWE-200
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 1, 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=beta < 2.8.0.beta9
  2. Affected versionversion=stable < 2.7.11
  3. Affected versionversion=tests-passed < 2.8.0.beta9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=beta < 2.8.0.beta9; version=stable < 2.7.11; version=tests-passed < 2.8.0.beta9

Published CVSS scores

4.3NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
3.5NVDAV:N/AC:M/Au:S/C:P/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

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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