VulnerabilityAnalyzed

CVE-2026-77247

In remote or multi-user deployments, a permitted client can disclose host files without shell or direct filesystem access.

HIGH 8.3EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). 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 and Confluence upload tools interpret caller-controlled path arguments on the MCP server and open those files before sending them as attachments. In remote or multi-user deployments, a permitted client can disclose host files without shell or direct filesystem access. The advisory traces the vulnerable input and processing flow through AttachmentsMixin.upload_attachment, AttachmentsMixin.upload_attachments, file_path, file_paths, and jira update_issue, 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: 0.39% probability · 33th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-73
Affected: mcp-atlassian/mcp atlassian
Source: security-advisories@github.com

EPSS trend

EPSS moved from 0.5% on 23 September 2026 to 0.4% on 26 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-f6pj-qv47-g96wExploit, Vendor Advisory
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f6pj-qv47-g96wExploit, Vendor Advisory

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