CVE-2026-77254

9.1 CRITICALpublic exploit available

Published 2026-09-22 · Updated 2026-09-28

AI risk analysis

Summary: The flaw allows network callers to perform operations with the operator account's permissions via the HTTP MCP endpoint without proper authentication, posing a critical risk.
Exploitability: Exploitation is relatively straightforward as it requires sending requests to the HTTP MCP endpoint without a per-user identity, which can be done by network callers.
Blast radius: If exploited, this can lead to unauthorized access and operations with high privileges, impacting the security and integrity of the Atlassian products Confluence and Jira.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to version 0.22.0 or later.

auth-bypasswebatlassianmcp

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

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 vector

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

Weaknesses

CWE-306

Vendors

mcp-atlassian

Products

mcp atlassian

Public exploit & PoC references

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460[Patch]
https://github.com/sooperset/mcp-atlassian/pull/1448[Issue Tracking, Patch]
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0[Release Notes]
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx[Exploit, Vendor Advisory]
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx[Exploit, Vendor Advisory]

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

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