High severity · published Aug 13, 2026
CVE-2026-72840
OpenWrt LuCI luci-mod-system-mounts ACL Root RCE via Crontab Write
8.8
CVSS
0.4%
EPSS
No
On KEV
Description
OpenWrt LuCI contains an overly permissive ACL definition in luci-mod-system-mounts that grants write access to /etc/crontabs/root to users intended only for mount configuration. Authenticated users with only the mount-configuration ACL group can append arbitrary cron entries via ubus file.write, which the default busybox crond daemon executes as root within one minute.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LU
luci · openwrt
through 24.10.8; 25.12.0 through 25.12.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-72840
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-72840
vendor-advisory
https://github.com/openwrt/luci/security/advisories/GHSA-v5f9-62c7-cw29
third-party-advisory
https://www.vulncheck.com/advisories/openwrt-luci-luci-mod-system-mounts-acl-root-rce-via-crontab-write
More from luci
9.9
CVE-2026-72842
OpenWrt luci-app-lxc ACL Inconsistency Authentication Bypass
9.9
CVE-2026-72841
luci-app-openvpn Path Traversal RCE via instance_name2
9.8
CVE-2019-12272
In OpenWrt LuCI through 0.10, the endpoints admin/status/realtime/bandwidth_status and admin/status/realtime/wireless_status of the web application are affected by a command…
8.8
CVE-2026-55897
luci-app-advanced-reboot read ACL exposes /bin/sh through file.exec, allowing delegated users to run commands as root
8.8
CVE-2026-69096
OpenWrt luci-app-dockerman Read ACL Remote Code Execution