CVE-2026-77251CWE-1276

CVE-2026-77251

Medium · published September 22, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
14.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
8.3 · 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
EPSS
0.00242 · 14.5th percentile
Weakness
CWE-1276 · Hardware Child Block Incorrectly Connected to Parent System
Published
2026-09-22T22:17Z
Affected products (1)
ProductVersionsFixed in
mcp-atlassian/mcp_atlassian< 0.22.00.22.0
References (5)
EPSS history
Timeline
  • 24 SEP 03:25Z
    EPSS moved — → 0%
    epss
  • 22 SEP 17:55Z
    MCP Atlassian: JIRA_PROJECTS_FILTER / CONFLUENCE_SPACES_FILTER allow forbidden-project content exfiltration (one LIVE-proven on Atlassian Cloud)
    cvelistv5