[mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| sooperset | mcp-atlassian | before 0.22.0 | 0.22.0 | Patch available | CNA |
| — | mcp-atlassian (PyPI) | before 0.22.0 | 0.22.0 | Patch available | GHSA-wrhw-j3f9-8vc6 |
- mcp-atlassian Vendorsooperset Affected before 0.22.0 Fixed in 0.22.0 Patch available CNA
- mcp-atlassian (PyPI) Vendor— Affected before 0.22.0 Fixed in 0.22.0 Patch available GHSA-wrhw-j3f9-8vc6
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:* | before 0.22.0 | Vulnerable | Mcp-atlassian |
- cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:* Versions before 0.22.0 Vulnerable ·Mcp-atlassian
Remediation
- Fix · CNA mcp-atlassian (sooperset) Fixed in 0.22.0
- Fix · GHSA-wrhw-j3f9-8vc6 mcp-atlassian (PyPI) Fixed in 0.22.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-77244
- 2026-10-03 Alias added: GHSA-wrhw-j3f9-8vc6
References
Patch 2
More sooperset vulnerabilities
- TI-2026-53938 MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials CVSS 3.1CRITICAL 9.1
- TI-2026-53957 MCP Atlassian: SSRF Protection Bypass CVSS 4.0HIGH 8.8
- TI-2026-53935 Protection mechanism failure in sooperset mcp-atlassian CVSS 4.0HIGH 8.3
- TI-2026-53946 Path traversal in sooperset mcp-atlassian CVSS 3.1HIGH 8.6
- TI-2026-53932 Path traversal in sooperset mcp-atlassian CVSS 3.1HIGH 8.6
- TI-2026-22177 Path traversal in sooperset mcp-atlassian CVSS 3.1CRITICAL 9.1
Sources
- CVE-2026-77244 · CVE Program
- CVE-2026-77244 · NVD
- FIRST EPSS
- GHSA-wrhw-j3f9-8vc6 · GitHub Advisory Database · CC BY 4.0
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