High 8.8Published Sep 21, 2026

CVE-2026-55159luci-app-adblock-fast: Delegated `luci-app-adblock-fast` users can reach root command execution by injecting newline-separated cron entries

Updated under an hour ago (2026-10-19 08:00 UTC)

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It affects openwrt luci-app-adblock-fast. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for openwrt luci-app-adblock-fast

Exploited in the last 30 days

luci-app-adblock-fast a WebUI for fast, lightweight DNS-based ad-blocker for OpenWrt that works with dnsmasq, smartdns, or unbound. Prior to 1.2.4-2, the luci.adblock-fast.setCronEntry RPC method accepts an entry argument containing carriage-return or line-feed characters and serializes it into /etc/crontabs/root as though it were one logical line. An authenticated delegated user with the luci-app-adblock-fast write ACL can therefore create an additional physical root cron entry through applications/luci-app-adblock-fast/root/usr/share/rpcd/ucode/luci.adblock-fast, resulting in persistent command execution as UID 0 when cron runs. The issue is not demonstrated for unauthenticated callers or users without the component write ACL. This vulnerability is fixed in 1.2.4-2.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-93
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 29, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

openwrt luci-app-adblock-fast openwrt:luci_app_adblock_fast (from the name)	before 1.2.4-2	CNA record

References

https://github.com/openwrt/luci/security/advisories/GHSA-ggpf-xrph-wg5vx-refsource-confirm
https://github.com/openwrt/luci/pull/8705x-refsource-misc
https://github.com/openwrt/luci/commit/9ccd99b5898457e5ef39dc21aea226d7fb6e5c7ex-refsource-misc
https://github.com/openwrt/luci/commit/f67461fd0255bf992b2b559c22ec288067f2f9dax-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.