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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Tencent Mass Service Engine in Cluster (MSEC) unknown
Version Status Constraints
0 affected < *

No data.

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/Tencent/MSEC cve-icon cve-icon
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-258-02.json cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-89040 cve-icon cve-icon
History

Tue, 15 Sep 2026 20:15:00 +0000

Type Values Removed Values Added
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.
Title Tencent Mass Service Engine in Cluster (MSEC) path traversal
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: cisa-cg

Published:

Updated: 2026-09-15T20:05:07.497Z

Reserved: 2026-09-10T16:43:38.518Z

Link: CVE-2026-89040

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-15T20:19:20.240

Modified: 2026-09-15T20:19:20.240

Link: CVE-2026-89040

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses