MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the OAuth error query parameter is passed to CallbackHandler._send_response in oauth_setup.py and interpolated into an HTML page without escaping. A crafted authorization callback can inject markup or script that executes in the browser of a user completing the OAuth flow. This issue is fixed in version 0.22.0.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-g2r2-3j32-j27x MCP Atlassian: Reflected XSS in OAuth Setup Callback Handler
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 23 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 22 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
First Time appeared Sooperset
Sooperset mcp-atlassian
Vendors & Products Sooperset
Sooperset mcp-atlassian

Tue, 22 Sep 2026 18:45:00 +0000

Type Values Removed Values Added
Description MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the OAuth error query parameter is passed to CallbackHandler._send_response in oauth_setup.py and interpolated into an HTML page without escaping. A crafted authorization callback can inject markup or script that executes in the browser of a user completing the OAuth flow. This issue is fixed in version 0.22.0.
Title MCP Atlassian: Reflected XSS in OAuth Setup Callback Handler
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-23T14:37:43.989Z

Reserved: 2026-08-20T19:14:21.330Z

Link: CVE-2026-77272

cve-icon Vulnrichment

Updated: 2026-09-23T14:10:20.335Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-22T19:16:51.177

Modified: 2026-09-23T18:12:04.247

Link: CVE-2026-77272

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-22T20:15:09Z

Weaknesses