# CVE-2026-89040

## Summary

- **CVE ID:** CVE-2026-89040
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-22
- **Published:** Sep 15, 2026
- **Last Modified:** Sep 15, 2026

## Description

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.

## Affected Products

- Tencent — Mass Service Engine in Cluster (MSEC) (0)

## References

- [CNA](https://github.com/Tencent/MSEC)
- [CNA](https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-258-02.json)
- [CNA](https://www.cve.org/CVERecord?id=CVE-2026-89040)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.93%
- **EPSS Percentile:** 58.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._