CVE-2026-77260: MCP Atlassian: Arbitrary local file READ via unconstrained file_path in upload_attachment (Confluence + Jira)
This is an arbitrary local file READ vulnerability on the Confluence and Jira upload_attachment tool paths. It’s the symmetric counterpart of the file-write vulnerability you patched as CVE-2026-27825. The write direction was fixed; the read direction was left open.
Reporter: Sean Valentine Severity: High (Critical in LLM-driven / prompt-injection deployments) Affected versions: main branch as of 2026-04-21. Both Confluence and Jira upload paths.
References
- github.com/advisories/GHSA-f4p7-qx46-wc5j
- 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-f4p7-qx46-wc5j
- nvd.nist.gov/vuln/detail/CVE-2026-77260
Code Behaviors & Features
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