Discourse up to 2026.1.5/2026.5.1/2026.6.0 Onebox onebox_handler.rb thread_id information disclosure

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.1$0-$5k0.50

Summaryinfo

A vulnerability, which was classified as problematic, was found in Discourse up to 2026.1.5/2026.5.1/2026.6.0. Affected is an unknown function of the file plugins/chat/lib/chat/onebox_handler.rb of the component Onebox. Executing a manipulation of the argument thread_id can lead to information disclosure. This vulnerability is registered as CVE-2026-72724. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability has been found in Discourse up to 2026.1.5/2026.5.1/2026.6.0 and classified as problematic. This vulnerability affects some unknown functionality of the file plugins/chat/lib/chat/onebox_handler.rb of the component Onebox. The manipulation of the argument thread_id with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. CVE summarizes:

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, plugins/chat/lib/chat/onebox_handler.rb resolves Chat::Thread by route thread_id independently of the route channel_id before checking whether the user can preview the selected chat channel. An authenticated user can pair a public channel ID with a private thread ID in a /onebox.json request and obtain private thread message content. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-72724 since 08/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 2026.1.6, 2026.5.2, 2026.6.1 or 2026.7.0 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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 2026.1.6/2026.5.2/2026.6.1/2026.7.0

Timelineinfo

08/10/2026 Advisory disclosed
08/10/2026 +0 days CVE reserved
08/10/2026 +0 days VulDB entry created
08/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-72724 (🔒)
GCVE (CVE): GCVE-0-2026-72724
GCVE (VulDB): GCVE-100-387760

Entryinfo

Created: 08/10/2026 18:27
Changes: 08/10/2026 18:27 (57)
Complete: 🔍
Cache ID: 216::103

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Discussion

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