CVE-2026-73497

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Source
https://cve.org/CVERecord?id=CVE-2026-73497
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73497.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-73497
Aliases
Published
2026-09-14T19:50:23Z
Modified
2026-09-18T11:47:01Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N CVSS Calculator
Summary
MCP Atlassian is a Model Context Protocol (MCP): DNS-rebinding TOCTOU bypass of the SSRF fix (CVE-2026-27826): unauthenticated SSRF to cloud metadata
Details

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). From 0.17.0 until 0.22.0, validate_url_for_ssrf resolves the attacker-controlled X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url header host once at middleware time, but the outbound request is built with the raw hostname and resolves it again at connection time with no IP pinning. An attacker-controlled DNS-rebinding name can return a public IP during validation and 169.254.169.254 or another internal IP during connection, enabling unauthenticated server-side requests to cloud metadata or internal services. The flaw spans src/mcp_atlassian/utils/urls.py, src/mcp_atlassian/servers/main.py, and src/mcp_atlassian/servers/dependencies.py; validate_url_for_ssrf returns only a verdict rather than a pinned IP, UserTokenMiddleware processes the attacker-controlled headers before fetcher creation, and the Jira and Confluence fetchers use the raw hostname. This issue is fixed in version 0.22.0.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73497.json"
}
References

Affected packages

Git / github.com/sooperset/mcp-atlassian

Affected ranges

Type
GIT
Repo
https://github.com/sooperset/mcp-atlassian
Events
Introduced
e191a2f2363b96d622599facafa3cf27ce2d3e44
Fixed
b041733473f95119dd539542a43c280737a8e460
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "0.17.0"
        },
        {
            "fixed": "0.22.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v0.*
v0.17.0
v0.18.0
v0.18.1
v0.19.0
v0.20.0
v0.20.1
v0.21.0
v0.21.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73497.json"