Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M

CVE-2026-77269MCP Atlassian: Path traversal in upload_attachment allows arbitrary file read (incomplete fix for CVE-2026-27825)

Medium 6.5

In plain English

A medium-severity path traversal in mcp-atlassian from sooperset. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 62.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the remediation for CVE-2026-27825 protects download destinations but does not constrain source paths used by attachment uploads. A caller can provide an absolute or traversal file_path and cause the server to upload the selected local file. 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	mcp-atlassian	0.22.0	GHSA-h7wj-5v37-59r2
PyPI	mcp-atlassian	0.22.0	PYSEC-2026-4095

Affected products (as reported)

Vendor	Product	Versions
sooperset	mcp-atlassian	< 0.22.0

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-h7wj-5v37-59r2 x_refsource_CONFIRM
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