MSRXCVE-2026-77254
CVE-2026-77254
MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials
CVSS 3.1 · CNA
chance of exploitation in the next 30 days (EPSS; higher than 49% of CVEs)
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Scores
Affected products
- sooperset mcp-atlassian: < 0.22.0
Weakness: CWE-306
Also known as: GHSA-vc8m-84rp-53hx
4 references (advisories, patches, write-ups)
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx · x_refsource_CONFIRM
- https://github.com/sooperset/mcp-atlassian/pull/1448 · x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 · x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 · x_refsource_MISC
Sources: CVE.org, OSV.dev, FIRST EPSS. Missing ones did not answer or have no record yet.