Discourse Email Formatting PrettyText.format_for_email cooked cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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3.4$0-$5k2.65-

Summaryinfo

A vulnerability described as problematic has been identified in Discourse. The affected element is the function PrettyText.format_for_email of the component Email Formatting. The manipulation of the argument cooked results in cross site scripting. This vulnerability is identified as CVE-2026-72720. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in Discourse. Affected is the function PrettyText.format_for_email of the component Email Formatting. The manipulation of the argument cooked with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. 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 traded as CVE-2026-72720 since 08/10/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 2026.1.7, 2026.6.2, 2026.7.1 or 2026.8.0-latest.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-55656). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
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: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
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-2026-72720 (🔒)
GCVE (CVE): GCVE-0-2026-72720
GCVE (VulDB): GCVE-100-387756
EUVD: 🔒

Entryinfo

Created: 08/10/2026 18:25
Updated: 08/10/2026 21:05
Changes: 08/10/2026 18:25 (56), 08/10/2026 21:05 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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