RCE in Openwrt Luci

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.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (51.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-55897: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55897?
CVE-2026-55897 is a high-severity vulnerability in Openwrt Luci, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-09-21.
How severe is CVE-2026-55897?
High severity. CVSS v3 base score is 8.8 out of 10.