{"id":"CVE-2026-55159","title":"luci-app-adblock-fast a WebUI for fast, lightweight DNS-based ad-blocker for OpenWrt that works with dnsmasq, smartdns, or unbound","summary":"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 carr…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-93"],"vendor":"openwrt","product":"luci-app-adblock-fast","affected":["luci-app-adblock-fast < 1.2.4-2"],"published":"2026-09-21","updated":"2026-09-24","sourceUpdated":"2026-09-24T21:25:27.050","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55159","references":[{"url":"https://github.com/openwrt/luci/commit/9ccd99b5898457e5ef39dc21aea226d7fb6e5c7e","label":"security-advisories@github.com"},{"url":"https://github.com/openwrt/luci/commit/f67461fd0255bf992b2b559c22ec288067f2f9da","label":"security-advisories@github.com"},{"url":"https://github.com/openwrt/luci/pull/8705","label":"security-advisories@github.com"},{"url":"https://github.com/openwrt/luci/security/advisories/GHSA-ggpf-xrph-wg5v","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"epss":0.00662,"epssPercentile":0.51442,"ingestedAt":"2026-09-21T19:51:58.875Z","slug":"CVE-2026-55159","body":"## Overview\n\nluci-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":212717,"id":"CVE-2026-55159","ts":1790693900078,"field":"exploit_available","old":"true","new":"false"},{"seq":212681,"id":"CVE-2026-55159","ts":1790692637779,"field":"exploit_available","old":"false","new":"true"}]}