Vulnerability details

CVE-2026-77260

sooperset mcp-atlassian

MCP Atlassian: Arbitrary local file READ via unconstrained file_path in upload_attachment (Confluence + Jira)

CVSS 4.0

8.3High

Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Confluence and Jira upload_attachment implementations accept an unconstrained file_path and open the referenced server-local file. A permitted MCP caller can upload sensitive host files to an Atlassian destination and then retrieve their contents. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

CVSS scores

Score	Version	Source	Vector
8.3High	4.0	CVEProject cvelistV5 (CNA) (GitHub_M)	`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`

Affected products

Vendor	Product	Versions	Source
sooperset	mcp-atlassian	< 0.22.0	CVEProject cvelistV5 (CNA)

References and advisories

https://github.com/sooperset/mcp-atlassian/pull/1448 x_refsource_MISC
https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 x_refsource_MISC
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 x_refsource_MISC
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f4p7-qx46-wc5j x_refsource_CONFIRM

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Details

Published: 2026-09-22
Last updated: 2026-09-26
State: Published
Assigner (CNA): GitHub_M

Exploit prediction (EPSS)

0.38%

Probability of exploitation in 30 days

32.7%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: Proof of concept
Technical impact: Total

Weaknesses (CWE)

CWE-22
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')