CVE-2026-77271: MCP Atlassian: Incomplete path traversal fix allows intra-CWD module overwrite and RCE (bypass of GHSA-xjgw-4wvw-rgm4)
The path traversal fix introduced in v0.17.0 (GHSA-xjgw-4wvw-rgm4) is incomplete. validate_safe_path() is called without an explicit base_dir, defaulting to os.getcwd(). In standard container deployments the process CWD is the application directory (e.g. /app), so paths within that directory, including the application’s own Python source modules, pass validation without
raising an exception. An attacker can overwrite a module file and achieve remote code execution on the next process restart. Versions >= 0.17.0 are not fully patched as stated in the original advisory. Confirmed on v0.21.0 (latest).
References
- github.com/advisories/GHSA-6vmq-24h2-pj7j
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
- github.com/sooperset/mcp-atlassian/pull/1448
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6vmq-24h2-pj7j
- nvd.nist.gov/vuln/detail/CVE-2026-77271
Code Behaviors & Features
Detect and mitigate CVE-2026-77271 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →