---
title: "CVE-2026-77243: MCP Atlassian - Broken Access Control"
description: "MCP Atlassian < 0.22.0 contains a broken access control vulnerability caused by improper rechecking of ENABLED_TOOLS and TOOLSETS during tools/call requests, letting clients invoke excluded read, write, or delete tools despite least-privilege restrictions, exploit requires knowledge of hidden tool names."
url: https://panop.io/threat-heartbeat/CVE-2026-77243/
---

# CVE-2026-77243 MCP Atlassian - Broken Access Control

MCP Atlassian < 0.22.0 contains a broken access control vulnerability caused by improper rechecking of ENABLED\_TOOLS and TOOLSETS during tools/call requests, letting clients invoke excluded read, write, or delete tools despite least-privilege restrictions, exploit requires knowledge of hidden tool names.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

Proof of concept available

EPSS

0.32% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-77243)

## Details

Type

Broken Access Control

Impact

Broken Access Control, Data Tampering, Information Disclosure

CVSS vector

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

Published

22 September 2026

Updated

15 October 2026

Weakness

[CWE-862](https://cwe.mitre.org/data/definitions/862.html)

## Vendor fix

Upgrade to version 0.22.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-77243](https://nvd.nist.gov/vuln/detail/CVE-2026-77243)
- [https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460](https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460)
- [https://github.com/sooperset/mcp-atlassian/pull/1448](https://github.com/sooperset/mcp-atlassian/pull/1448)
- [https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0](https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0)
- [https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-3r68-hf9h-887v](https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-3r68-hf9h-887v)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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