Critical 10.0Published Sep 22, 2026

CVE-2026-77244[mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token

Updated under an hour ago (2026-10-19 07:00 UTC)

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It affects sooperset mcp-atlassian and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for sooperset mcp-atlassian

Exploited in the last 30 days

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 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Weakness (CWE): CWE-287, CWE-303, CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Sep 23, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

sooperset mcp-atlassian sooperset:mcp_atlassian (from the name)	before 0.22.0	CNA record
mcp-atlassian mcp_atlassian mcp-atlassian:mcp_atlassian	before 0.22.0	NVD

References

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wrhw-j3f9-8vc6x-refsource-confirm, exploit, vendor-advisory
https://github.com/sooperset/mcp-atlassian/pull/1448x-refsource-misc, patch
https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460x-refsource-misc, patch
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.