CVE-2026-77251
MCP Atlassian: JIRA_PROJECTS_FILTER / CONFLUENCE_SPACES_FILTER allow forbidden-project content exfiltration (one LIVE-proven on Atlassian Cloud)
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, Jira search accepts a forbidden project clause because it checks only for the presence of project syntax, Confluence search uses an incomplete case-sensitive space check, and Jira board APIs omit project-filter enforcement. These paths expose issues, boards, or pages outside JIRA_PROJECTS_FILTER or CONFLUENCE_SPACES_FILTER when the operator credentials have broader access. The advisory traces the vulnerable input and processing flow through jira_search, confluence_search, get_board_issues, get_agile_boards, JIRA_PROJECTS_FILTER, and CONFLUENCE_SPACES_FILTER, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
- Affected
- sooperset · mcp-atlassian
- CVSS v4.0 GITHUB
- 8.3 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v4.0 GitHub
- 8.3 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N - CVSS v3.1 NVD
- 6.5 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - EPSS
- 0.24% chance of exploitation in the next 30 days, 14th percentile
- Published
- 2026-09-22
- Updated
- 2026-09-25