CVSS 3.1
10.0 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:NCVE-2026-77244
Critical (10.0) 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 HTTP transport accepts requests without a verified user identity and downstream fetcher construction falls back to the operator's globally configured Jira or Confluence credentials. A network client that can reach the MCP endpoint can invoke Atlassian tools as the operator, including read and write operations available to that account. The advisory traces the vulnerable input and processing flow through UserTokenMiddleware, AtlassianOpaqueTokenVerifier, _get_fetcher, and streamable-http, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 28% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-287, CWE-303, CWE-862
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mcp-atlassian:mcp_atlassian
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-wrhw-j3f9-8vc6 | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |
| PYSEC-2026-4103 | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |