Discourse up to 2026.1.4/2026.4.1/2026.5.0 Delete Confirmation Dialog cross site scripting

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
2.3$0-$5k0.59

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. This affects an unknown part of the component Delete Confirmation Dialog. The manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-53963. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Discourse up to 2026.1.4/2026.4.1/2026.5.0 and classified as problematic. This issue affects an unknown functionality of the component Delete Confirmation Dialog. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. The summary by CVE is:

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that account. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-53963 since 06/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are required for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 2026.6.0, 2026.5.1, 2026.4.2 or 2026.1.5 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.4
VulDB Meta Temp Score: 2.3

VulDB Base Score: 2.4
VulDB Temp Score: 2.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
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: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 2026.6.0/2026.5.1/2026.4.2/2026.1.5

Timelineinfo

06/11/2026 CVE reserved
07/09/2026 +28 days VulDB entry created
07/10/2026 +0 days Advisory disclosed
07/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-53963 (🔒)
GCVE (CVE): GCVE-0-2026-53963
GCVE (VulDB): GCVE-100-377357

Entryinfo

Created: 07/10/2026 01:13
Changes: 07/10/2026 01:13 (53)
Complete: 🔍
Cache ID: 216::103

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Discussion

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