CVE-2026-89040 Tencent Mass Service Engine in Cluster (MSEC) path traversal
Remote unauthenticated attackers can exploit path traversal to upload a webshell and execute arbitrary code with root privileges on Tencent MSEC devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-89040?
CVE-2026-89040 is a critical path traversal vulnerability in Tencent Mass Service Engine in Cluster (MSEC), published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2026-89040?
How do I fix CVE-2026-89040?
No fix has been published for CVE-2026-89040 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-89040 being exploited?
There is no known exploitation of CVE-2026-89040 in the wild and no public exploit code.
Sources
Also known as GHSA-wfq6-vqf6-g78h.