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Medium severity · published Sep 22, 2026
CVE-2026-77247
MCP Atlassian: Arbitrary server-local file upload to Jira/Confluence attachments via unrestricted file_path parameters
6.5
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
mcp-atlassian · sooperset
< 0.22.0 · source: vendor
MA
Mcp Atlassian · Mcp-atlassian
before 0.22.0 · source: NVD
Affected product
MC
mcp-atlassian
sooperset
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77247
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77247
Patch
https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
Issue Tracking
https://github.com/sooperset/mcp-atlassian/pull/1448
Release Notes
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
Exploit
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f6pj-qv47-g96w
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