CVE-2026-77244

critical

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).

Vendor / product: Mcp-atlassian — mcp atlassian

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the HTTP transport accepts requests without a verified user identity and downstream fetcher construction falls back to the operator's globally configured Jira or Confluence credentials. A network client that can reach the MCP endpoint can invoke Atlassian tools as the operator, including read and write operations available to that account. The advisory traces the vulnerable input and processing flow through UserTokenMiddleware, AtlassianOpaqueTokenVerifier, _get_fetcher, and streamable-http, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

CVSS

10.0

10.0 (CVSS v3.1)

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

Severity source: NVD CVSS v3.1 (security-advisories@github.com)

Timeline (UTC)

Published: 2026-09-22 18:17

Modified: 2026-09-29 15:17

NVD status: Analyzed

Last synced 2 days ago

Verified against the source API 2026-10-27 06:55 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

mcp-atlassian / mcp_atlassian <0.22.0

Weakness classification (CWE)

CWE-287 CWE-303 CWE-862

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wrhw-j3f9-8vc6

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

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

References

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/pull/1448 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wrhw-j3f9-8vc6 security-advisories@github.com

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:55 UTC · record ↗

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CVE-2026-77244

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