CVE-2026-77243

8.8 HIGHpublic exploit available

Published 2026-09-22 · Updated 2026-09-23

AI risk analysis

Summary: The flaw allows a client to invoke hidden tools despite configured least-privilege restrictions, leading to potential unauthorized access to read, write, or delete operations.
Exploitability: Exploitation is moderately hard as it requires knowledge of hidden tool names, but once obtained, the attack can bypass security controls.
Blast radius: If exploited, this could lead to significant data breaches or system compromise, affecting Confluence and Jira users.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to MCP Atlassian 0.22.0 or later.

auth-bypasswebatlassian

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, ENABLED_TOOLS and TOOLSETS are applied when tools are listed but are not rechecked when a tools/call request is dispatched. A client that knows a hidden tool name can directly invoke excluded read, write, or delete tools despite the operator's configured least-privilege restrictions. The advisory traces the vulnerable input and processing flow through ENABLED_TOOLS, TOOLSETS, tools/list, tools/call, and _call_tool_mcp, 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:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses

CWE-862

Public exploit & PoC references

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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