Discourse up to 2026.1.1/2026.2.0/2026.3.0-latest Setting exclude_groups information exposure

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability was found in Discourse up to 2026.1.1/2026.2.0/2026.3.0-latest. It has been rated as problematic. Impacted is an unknown function of the component Setting Handler. The manipulation of the argument exclude_groups leads to information exposure. This vulnerability is uniquely identified as CVE-2026-33425. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Discourse up to 2026.1.1/2026.2.0/2026.3.0-latest and classified as problematic. This issue affects an unknown function of the component Setting Handler. The manipulation of the argument exclude_groups with an unknown input leads to a information exposure vulnerability. Using CWE to declare the problem leads to CWE-203. The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not. Impacted is confidentiality. The summary by CVE is:

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, unauthenticated users can determine whether a specific user is a member of a private group by observing changes in directory results when using the `exclude_groups` parameter. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable public access to the user directory via Admin → Settings → hide user profiles from public.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-33425 since 03/19/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading to version 2026.1.2 or 2026.2.1 eliminates this vulnerability.

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Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Information exposure
CWE: CWE-203 / CWE-200 / CWE-284
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 2026.1.2/2026.2.1

Timelineinfo

03/19/2026 CVE reserved
03/21/2026 +2 days Advisory disclosed
03/21/2026 +0 days VulDB entry created
03/27/2026 +6 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-r6rh-xvf5-r5f2
Status: Confirmed

CVE: CVE-2026-33425 (🔒)
GCVE (CVE): GCVE-0-2026-33425
GCVE (VulDB): GCVE-100-352247

Entryinfo

Created: 03/21/2026 07:49
Updated: 03/27/2026 09:08
Changes: 03/21/2026 07:49 (69), 03/27/2026 09:08 (11)
Complete: 🔍
Cache ID: 216::103

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