CVE-2026-77261
Received Received - Intake

Open Redirect in MCP Atlassian Prior to 0.22.0

Publication date: 2026-09-22

Last updated on: 2026-09-22

Assigner: GitHub, Inc.

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.

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Meta Information

Published
2026-09-22
Last Modified
2026-09-22
Generated
2026-09-22
AI Q&A
2026-09-22
EPSS Evaluated
N/A
NVD
CVE-2026-77261
EUVD
EUVD-2026-84631

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
atlassian mcp 0.22.0
sooperset mcp-atlassian 0.22.0
atlassian confluence *
atlassian jira *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

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Executive Summary

CVE-2026-77261 is a Server-Side Request Forgery (SSRF) vulnerability in the MCP Atlassian package affecting versions before 0.22.0. The issue occurs because SSRF redirect protection is missing in sessions created via basic-auth and OAuth authentication methods. Attackers who control or compromise an Atlassian instance can manipulate it to return malicious redirects to internal addresses, which the vulnerable MCP server follows without validation.

Detection Guidance

To detect this vulnerability, check if your mcp-atlassian instance is running a version prior to 0.22.0. Use commands like 'pip show mcp-atlassian' or 'pip list' to verify the installed version. Inspect server logs for unusual redirect patterns or internal network requests originating from the MCP server.

Impact Analysis

This vulnerability allows attackers to redirect server requests to internal infrastructure, potentially exposing sensitive data like AWS IAM credentials. Attackers could access internal services or cloud metadata endpoints, leading to data breaches or unauthorized access to confidential information.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating compliance requirements under GDPR and HIPAA. GDPR requires protecting personal data, while HIPAA mandates safeguarding protected health information. A breach could result in legal penalties and reputational damage.

Mitigation Strategies

Upgrade to mcp-atlassian version 0.22.0 or later immediately. If upgrading is not possible, ensure SSRF redirect hooks are enabled by setting 'attach_ssrf_hook=True' in the basic-auth and OAuth branches. Review and restrict network access to prevent internal service exposure.

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