CVE-2026-77261

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.

Score

CVSS 3.1 8.5 High

Status

Analyzed - security-advisories@github.com

Published

2026-09-22

Last modified

2026-09-23

Weaknesses

CWE-918

Affected products

• Mcp Atlassian (Mcp-atlassian)
• Mcp-atlassian (Sooperset)

References

• https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
• https://github.com/sooperset/mcp-atlassian/pull/1448
• https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
• https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6529-c226-h328