CVE-2026-77260
HIGHMCP 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...
Full CISO analysis pending enrichment.
What systems are affected?
| Package | Ecosystem | Vulnerable Range | Patched |
|---|---|---|---|
| MCP Atlassian | pip | — | No patch |
Do you use MCP Atlassian? You're affected.
How severe is it?
What should I do?
No patch available
Monitor for updates. Consider compensating controls or temporary mitigations.
Which compliance frameworks are affected?
Compliance analysis pending. Sign in for full compliance mapping when available.
Frequently Asked Questions
What is CVE-2026-77260?
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.
Is CVE-2026-77260 actively exploited?
No confirmed active exploitation of CVE-2026-77260 has been reported, but organizations should still patch proactively.
How to fix CVE-2026-77260?
No patch is currently available. Monitor vendor advisories for updates.
What is the CVSS score for CVE-2026-77260?
No CVSS score has been assigned yet.
What are the technical details?
Original Advisory
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.
Weaknesses (CWE)
CWE-22 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'): The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
- [Implementation] Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylis
- [Architecture and Design] For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Source: MITRE CWE corpus.
References
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 x_refsource_MISC
- github.com/sooperset/mcp-atlassian/pull/1448 x_refsource_MISC
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 x_refsource_MISC
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f4p7-qx46-wc5j x_refsource_CONFIRM
Timeline
Related Vulnerabilities
CVE-2026-77244 10.0 Analysis pending
Same package: mcp-atlassian CVE-2026-27825 9.1 mcp-atlassian: Path Traversal enables file access
Same package: mcp-atlassian CVE-2026-77243 8.8 Analysis pending
Same package: mcp-atlassian CVE-2026-27826 8.2 mcp-atlassian: SSRF allows internal network access
Same package: mcp-atlassian GHSA-wm45-qh3g-v83f 7.7 mcp-atlassian: path traversal leaks server files+creds
Same package: mcp-atlassian