VulnerabilityAnalyzed

CVE-2026-77251

These paths expose issues, boards, or pages outside JIRA_PROJECTS_FILTER or CONFLUENCE_SPACES_FILTER when the operator credentials have broader access.

HIGH 8.3EPSS 0.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0: 8.3 HIGHCVSS: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/M
EPSS: 0.27% probability · 18th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-1276
Affected: mcp-atlassian/mcp atlassian
Source: security-advisories@github.com

EPSS trend

EPSS moved from 0.4% on 23 September 2026 to 0.3% on 27 October 2026.

References

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460Patch
https://github.com/sooperset/mcp-atlassian/pull/1448Issue Tracking, Patch
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0Release Notes
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-w66g-j6c4-hcfcExploit, Mitigation, Vendor Advisory
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-w66g-j6c4-hcfcExploit, Mitigation, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.