CVE-2026-77254: critical vulnerability in sooperset mcp-atlassian
MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 0.6%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected products
sooperset · mcp-atlassianRelated CVEs — sooperset mcp-atlassian
In the same product, most dangerous first.
CVE-2026-27826HIGHMCP Atlassian has SSRF via unvalidated X-Atlassian-Jira-Url / X-Atlassian-Confluence-Url headersEPSS 13.9%CVE-2026-27825CRITICALMCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachmentEPSS 12.3%CVE-2026-77271HIGHMCP Atlassian: Incomplete path traversal fix allows intra-CWD module overwrite and RCE (bypass of CVE-2026-27825)EPSS 0.6%CVE-2026-77262HIGHMCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)EPSS 0.6%CVE-2026-77243HIGHMCP Atlassian: ENABLED_TOOLS / Toolset authorization bypassEPSS 0.5%CVE-2026-124503MEDIUMsooperset mcp-atlassian io.py validate_safe_path path traversalEPSS 0.5%