CVSS 3.1
6.1 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NCVE-2026-77272
Medium (6.1) in mcp-atlassian mcp atlassian. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in mcp-atlassian 0.22.0.
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.
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 18% of CVEs (scores of 2026-10-31)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mcp-atlassian:mcp_atlassian
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-g2r2-3j32-j27x | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |
| PYSEC-2026-4093 | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |