---
id: CVE-2026-77268
title: >-
  MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products
  (Confluence and Jira)
summary: >-
  MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products
  (Confluence and Jira). Prior to 0.22.0, the OAuth fallback token directory and
  JSON file are created without explicit owner-only modes. Local users or
  processe…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-732
vendor: sooperset
product: mcp-atlassian
affected:
  - mcp-atlassian < 0.22.0
patched:
  - mcp-atlassian 0.22.0
published: '2026-09-22'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T18:12:04.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77268'
references:
  - url: >-
      https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
    label: security-advisories@github.com
  - url: 'https://github.com/sooperset/mcp-atlassian/pull/1448'
    label: security-advisories@github.com
  - url: 'https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-4596-2p6p-28cv
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-4596-2p6p-28cv'
  - url: 'https://github.com/sooperset/mcp-atlassian'
tags:
  - nvd
  - cve.org
  - ghsa
  - pip
  - osv
epss: 0.00111
epssPercentile: 0.01234
aliases:
  - GHSA-4596-2p6p-28cv
ecosystem: pip
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T14:10:18.373472Z'
ingestedAt: '2026-09-22T19:09:10.005Z'
---

## Overview

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the OAuth fallback token directory and JSON file are created without explicit owner-only modes. Local users or processes with access through the resulting group or world permission bits can read access and refresh tokens and reuse the associated Atlassian session. The advisory traces the vulnerable input and processing flow through ~/.mcp-atlassian, oauth-<client_id>.json, access_token, and refresh_token, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-77268)

Affected packages:

- `mcp-atlassian < 0.22.0`

Patched in:

- `mcp-atlassian 0.22.0`

Source: https://github.com/advisories/GHSA-4596-2p6p-28cv