CVE-2026-77253

high

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).

Vendor / product: Mcp-atlassian — mcp atlassian

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, Jira and Confluence attachment upload tools accept arbitrary local filesystem paths and send the selected bytes to Atlassian. In HTTP or multi-user deployments, a caller can cross the client-to-server filesystem boundary and disclose configuration, credentials, mounted secrets, or other files readable by the MCP process. The advisory traces the vulnerable input and processing flow through jira_upload_attachment, confluence_upload_attachment, file_path, and server-local filesystem, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

CVSS

7.1

7.1 (CVSS v3.1)

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Severity source: NVD CVSS v3.1 (security-advisories@github.com)

Timeline (UTC)

Published: 2026-09-22 19:16

Modified: 2026-09-28 13:23

NVD status: Analyzed

Last synced 2 days ago

Verified against the source API 2026-10-27 06:55 UTC

Exploitation

Not listed in CISA KEV (as of last catalog sync)

Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

mcp-atlassian / mcp_atlassian <0.22.0

Weakness classification (CWE)

CWE-22

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc25-24vv-fxxm

Patch / mitigation: https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460

Patch / mitigation: https://github.com/sooperset/mcp-atlassian/pull/1448

References

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/pull/1448 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc25-24vv-fxxm security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc25-24vv-fxxm 134c704f-9b21-4f2e-91b3-4a467353bcc0

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:55 UTC · record ↗

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CVE-2026-77253

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Weakness classification (CWE)

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