SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-72840

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.

HIGH 8.7EPSS 0.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.38% probability · 32th percentile
CISA KEV
Not listed
Weakness
CWE-266
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.