CVE-2026-79537

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Source
https://cve.org/CVERecord?id=CVE-2026-79537
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-79537.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-79537
Published
2026-09-29T00:00:00Z
Modified
2026-10-02T03:31:04Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
[none]
Details

metatool-ai MetaMCP through 2.4.22 contains an insecure direct object reference (IDOR) in the MCP transport session dispatch. The session store (getSession in session-lifetime-manager.ts) is keyed only by the client-supplied mcp-session-id header with no owner, namespace, or endpoint binding, and the per-endpoint authorization middleware validates only the URL endpoint's owner, never the session. An attacker who supplies another tenant's session id " obtained without authentication from GET /metamcp/health/sessions, which discloses active session IDs and namespace UUIDs " can list and execute the victim tenant's private MCP tools and exfiltrate their data using the victim's forwarded credentials.

Database specific 
{
    "cna_assigner":  "mitre",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79537.json"
}
References

Affected packages

Git / github.com/metatool-ai/metamcp

Affected ranges

Type
GIT
Repo
https://github.com/metatool-ai/metamcp
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
32b6e9813acfc13d1013eb2452be1899d6654bb9
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "2.4.22"
        }
    ],
    "source":  "DESCRIPTION"
}

Affected versions

v0.*
v0.0.1
v0.0.2
v0.3.2
v0.4.0
v0.4.2
v0.4.3
v0.4.5
v0.5.0
v0.5.2
v0.5.3
v0.6.0
v2.*
v2.0.0
v2.0.1
v2.0.2
v2.0.3
v2.0.5
v2.0.6
v2.1.0
v2.1.1
v2.2.0
v2.2.1
v2.2.2
v2.2.3
v2.2.4
v2.2.5
v2.3.0
v2.3.1
v2.3.2
v2.3.3
v2.3.4
v2.3.5
v2.3.6
v2.3.7
v2.3.8
v2.4.10
v2.4.11
v2.4.12
v2.4.13
v2.4.14
v2.4.15
v2.4.16
v2.4.17
v2.4.18
v2.4.19
v2.4.20
v2.4.21
v2.4.5
v2.4.6
v2.4.7
v2.4.8
v2.4.9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-79537.json"