8.8High

CVE-2026-55897

luci-app-advanced-reboot is a LuCI (web interface) application for OpenWrt that provides a way to reboot your router into an alternative firmware partition or perform reboot operations directly from the web UI. Prior to 1.1.2-6, the luci-app-advanced-reboot read ACL in applications/luci-app-advanced-reboot/root/usr/share/rpcd/acl.d/luci-app-advanced-reboot.json grants rpcd file.exec permission for the general shell interpreter /bin/sh. An authenticated delegated session with that read ACL can supply caller-controlled params; rpcd authorizes the executable path and passes those arguments to the shell, allowing arbitrary commands to execute as root. Builds without the /bin/sh exec grant, including the checked openwrt-24.10 and openwrt-23.05 branches, are not affected by this specific chain. This vulnerability is fixed in 1.1.2-6.

What this means for your business

  • An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 39% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
8.8 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness
CWE-78
Assigned by
security-advisories@github.com

Dates

Published
2026-09-21
Last modified
2026-09-21
Sources
NVD

References