CVE-2026-77261

high

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.

References

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6529-c226-h328

https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0

https://github.com/sooperset/mcp-atlassian/pull/1448

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460

Details

Source: Mitre, NVD

Published: 2026-09-22

Updated: 2026-09-25

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:P/A:N

Severity: High

CVSS v3

Base Score: 8.5

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Severity: High

EPSS

EPSS: 0.00323