What is CVE-2026-89040?

CVE-2026-89040 is a critical-severity vulnerability in Tencent Mass Service Engine In Cluster (Msec), classified under Path Traversal. CVSS score: 9.8/10. Published 2026-09-15.

How severe is CVE-2026-89040?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Path Traversal in Tencent Mass Service Engine In Cluster (Msec)

CVE-2026-89040

Tencent Mass Service Engine in Cluster (MSEC) allows a remote, unauthenticated attacker to send a crafted POST request including ../ and gain root access on the target device. An attacker who uploads a webshell can execute arbitrary code as root.

Vulnerability class: Path Traversal (Directory Traversal)

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Tencent Mass Service Engine In Cluster (Msec)

Weakness classification (CWE)

CWE-22 — Path Traversal

References

9119a7d8-5eab-497f-8521-727c672e3725 (product)
9119a7d8-5eab-497f-8521-727c672e3725 (third-party-advisory)
9119a7d8-5eab-497f-8521-727c672e3725 (vdb-entry)

Frequently asked questions

What is CVE-2026-89040?: CVE-2026-89040 is a critical-severity vulnerability in Tencent Mass Service Engine In Cluster (Msec), classified under Path Traversal. CVSS score: 9.8/10. Published 2026-09-15.
How severe is CVE-2026-89040?: Critical severity. CVSS v3 base score is 9.8 out of 10.