MSRXCVE-2026-77271
CVE-2026-77271
MCP Atlassian: Incomplete path traversal fix allows intra-CWD module overwrite and RCE (bypass of CVE-2026-27825)
CVSS 4.0 · CNA · github.com
chance of exploitation in the next 30 days (EPSS; higher than 48% of CVEs)
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_safe_path defaults its base directory to os.getcwd(), and affected Confluence attachment call sites omit base_dir, allowing attacker-selected writes within the working directory. This Python module overwrite can provide code execution when the application later imports the modified module, bypassing the remediation tracked as CVE-2026-27825. This issue is fixed in version 0.22.0.
Scores
Affected packages and fixed versions
| Package | Ecosystem | Fixed in |
|---|---|---|
| mcp-atlassian | PyPI | 0.22.0 |
Affected products
- mcp-atlassian mcp atlassian: < 0.22.0
Also known as: GHSA-6vmq-24h2-pj7j, PYSEC-2026-4087
4 references (advisories, patches, write-ups)
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 · Patch
- https://github.com/sooperset/mcp-atlassian/pull/1448 · Issue Tracking, Patch
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 · Release Notes
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6vmq-24h2-pj7j · Exploit, Vendor Advisory
Sources: NVD, CVE.org, OSV.dev, FIRST EPSS. Missing ones did not answer or have no record yet.