CVE-2026-89040

9.3 criticalEPSS 1.1%

Critical (9.3). EPSS 1.1% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

9.3 critical

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

CVSS 3.1

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)
CWE: CWE-22
Published: 2026-09-15
Modified: 2026-09-22
Record from: the NVD, synced 2026-10-19

References

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

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