Discourse Onebox input validation

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-$5k1.05

Summaryinfo

A vulnerability was found in Discourse up to 2026.1.6/2026.6.1/2026.7.0/2026.8.0-latest.0 and classified as problematic. This issue affects some unknown processing of the component Onebox. Such manipulation leads to input validation. This vulnerability is documented as CVE-2026-72728. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Discourse up to 2026.1.6/2026.6.1/2026.7.0/2026.8.0-latest.0. Affected by this issue is an unknown code of the component Onebox. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is integrity. CVE summarizes:

Discourse is an open-source discussion platform. Prior to 2026.1.7, an authenticated user could submit specially formed URLs that bypassed the Onebox allowlist and embedded malicious content in a site. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-72728 since 08/10/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 2026.1.7, 2026.6.2, 2026.7.1 or 2026.8.0-latest.1 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: Input validation
CWE: CWE-20
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 2026.1.7/2026.6.2/2026.7.1/2026.8.0-latest.1

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-2026-72728 (🔒)
GCVE (CVE): GCVE-0-2026-72728
GCVE (VulDB): GCVE-100-387776

Entryinfo

Created: 08/10/2026 18:38
Changes: 08/10/2026 18:38 (55)
Complete: 🔍
Cache ID: 216::103

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