CVE-2023-23624

Discourse's exclude_tags param could leak which topics had a specific hidden tag

MEDIUM
5.3
CVSS Score
Published: January 27, 2023 at 11:35 PM UTC
Updated: June 17, 2026 at 05:37 AM UTC
1 product affected across 1 vendorDiscourse

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, someone can use the `exclude_tag param` to filter out topics and deduce which ones were using a specific hidden tag. This affects any Discourse site using hidden tags in public categories. This issue is patched in version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches. As a workaround, secure any categories that are using hidden tags, change any existing hidden tags to not include private data, or remove any hidden tags currently in use.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.0.11.1.0 beta11.1.0 beta21.1.0 beta31.1.0 beta41.1.0 beta51.1.0 beta61.1.0 beta6b1.1.0 beta71.1.0 beta81.2.0 beta11.2.0 beta21.2.0 beta31.2.0 beta41.2.0 beta51.2.0 beta61.2.0 beta71.2.0 beta81.2.0 beta91.3.0 beta11.3.0 beta101.3.0 beta111.3.0 beta21.3.0 beta31.3.0 beta41.3.0 beta51.3.0 beta61.3.0 beta71.3.0 beta81.3.0 beta91.4.0 beta11.4.0 beta101.4.0 beta111.4.0 beta121.4.0 beta21.4.0 beta31.4.0 beta41.4.0 beta51.4.0 beta61.4.0 beta71.4.0 beta81.4.0 beta91.5.0 beta11.5.0 beta101.5.0 beta111.5.0 beta121.5.0 beta131.5.0 beta13b1.5.0 beta141.5.0 beta21.5.0 beta31.5.0 beta41.5.0 beta51.5.0 beta61.5.0 beta71.5.0 beta81.5.0 beta91.6.0 beta11.6.0 beta101.6.0 beta111.6.0 beta121.6.0 beta21.6.0 beta31.6.0 beta41.6.0 beta51.6.0 beta61.6.0 beta71.6.0 beta81.6.0 beta91.7.0 beta11.7.0 beta101.7.0 beta111.7.0 beta21.7.0 beta31.7.0 beta41.7.0 beta51.7.0 beta61.7.0 beta71.7.0 beta81.7.0 beta91.8.0 beta11.8.0 beta101.8.0 beta111.8.0 beta121.8.0 beta131.8.0 beta21.8.0 beta31.8.0 beta41.8.0 beta51.8.0 beta61.8.0 beta71.8.0 beta81.8.0 beta91.9.0 beta11.9.0 beta101.9.0 beta111.9.0 beta121.9.0 beta131.9.0 beta141.9.0 beta151.9.0 beta161.9.0 beta171.9.0 beta21.9.0 beta31.9.0 beta41.9.0 beta51.9.0 beta61.9.0 beta71.9.0 beta81.9.0 beta92.0.0 beta12.0.0 beta102.0.0 beta22.0.0 beta32.0.0 beta42.0.0 beta52.0.0 beta62.0.0 beta72.0.0 beta82.0.0 beta92.1.0 beta12.1.0 beta22.1.0 beta32.1.0 beta42.1.0 beta52.1.0 beta62.2.0 beta12.2.0 beta102.2.0 beta22.2.0 beta32.2.0 beta42.2.0 beta52.2.0 beta62.2.0 beta72.2.0 beta82.2.0 beta92.3.0 beta12.3.0 beta102.3.0 beta112.3.0 beta22.3.0 beta32.3.0 beta42.3.0 beta52.3.0 beta62.3.0 beta72.3.0 beta82.3.0 beta92.4.0 beta12.4.0 beta102.4.0 beta112.4.0 beta22.4.0 beta32.4.0 beta42.4.0 beta52.4.0 beta62.4.0 beta72.4.0 beta82.4.0 beta92.5.0 beta12.5.0 beta22.5.0 beta32.5.0 beta42.5.0 beta52.5.0 beta62.5.0 beta72.6.0 beta12.6.0 beta22.6.0 beta32.6.0 beta42.6.0 beta52.6.0 beta62.7.0 beta12.7.0 beta22.7.0 beta32.7.0 beta42.7.0 beta52.7.0 beta62.7.0 beta72.7.0 beta82.7.0 beta92.8.0 beta12.8.0 beta102.8.0 beta112.8.0 beta22.8.0 beta32.8.0 beta42.8.0 beta52.8.0 beta62.8.0 beta72.8.0 beta82.8.0 beta92.9.0 beta12.9.0 beta102.9.0 beta112.9.0 beta122.9.0 beta132.9.0 beta142.9.0 beta22.9.0 beta32.9.0 beta42.9.0 beta52.9.0 beta62.9.0 beta72.9.0 beta82.9.0 beta93.0.0 beta153.0.0 beta163.1.0 beta1= 3.1.0.beta1
Affected range stops below 3.0.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-200

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