CVE-2026-77261

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

Published Sep 22, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-6529-c226-h328 MCP Atlassian: SSRF redirect protection missing for basic-auth and OAuth authentication branches
History
Type Values Removed Values Added
First Time appeared Mcp-atlassian
Mcp-atlassian mcp Atlassian
CPEs cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*
Vendors & Products Mcp-atlassian
Mcp-atlassian mcp Atlassian
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
First Time appeared Sooperset
Sooperset mcp-atlassian
Vendors & Products Sooperset
Sooperset mcp-atlassian
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, _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.
Title MCP Atlassian: SSRF redirect protection missing for basic-auth and OAuth authentication branches
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 23, 2026, 2:38 PM
Reserved
Aug 20, 2026, 7:02 PM
Status
Analyzed
Published
Sep 22, 2026, 6:17 PM
Modified
Sep 25, 2026, 5:36 PM