cybersec
Aug 7, 2026 · 6 min Command InjectionCVE-2026-38835: The Format String That Handed Out a Shell
A Tenda W30E V2.0 web handler takes a JSON field called `usbPartitionName`, splices it straight into a `/usr/sbin/usb umount %s` command line, and hands the result to a `system()` wrapper. No escaping, no allow-list, no shell-metacharacter filter — just a `%s` where a device path was supposed to go.
— a %s where a partition should be