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TI-2026-53945 Aliases CVE-2026-77261GHSA-6529-c226-h328

MCP Atlassian: SSRF redirect protection missing for basic-auth and OAuth authentication branches

Priority LOW 37CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, _make_ssrf_safe_hook is omitted from JiraFetcher and ConfluenceFetcher sessions created through the basic-auth and oauth_pat branches. If an attacker-controlled or compromised configured Atlassian instance returns a redirect to an internal address, those sessions can follow the redirect without revalidating its destination. This issue is fixed in version 0.22.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00373 31st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed mcp-atlassian (sooperset): 0.22.0mcp-atlassian (PyPI): 0.22.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
soopersetmcp-atlassianbefore 0.22.00.22.0Patch availableCNA
—mcp-atlassian (PyPI)before 0.22.00.22.0Patch availableGHSA-6529-c226-h328
  • 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-6529-c226-h328

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*before 0.22.0VulnerableMcp-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-6529-c226-h328 mcp-atlassian (PyPI) Fixed in 0.22.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-77261
  2. 2026-10-03 Alias added: GHSA-6529-c226-h328

References

  • 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
See all 33 →

Sources