Command Injection Vulnerability in luci-app-adblock-fast by OpenWrt
CVE-2026-55159

8.8HIGH

Key Information:

Vendor

Openwrt

Status
Luci-app-adblock-fast
Vendor
CVE Published:
21 September 2026

What is CVE-2026-55159?

The luci-app-adblock-fast, a user interface for a lightweight DNS-based ad-blocker designed for OpenWrt, is susceptible to a command injection vulnerability. The issue arises from the luci.adblock-fast.setCronEntry RPC method, which incorrectly handles carriage-return or line-feed characters. This vulnerability allows an authenticated user with write access to create a malicious cron job that executes commands as UID 0 when cron runs. This security flaw is present in versions prior to 1.2.4-2 and has been addressed in the subsequent release.

Affected Version(s)

luci-app-adblock-fast < 1.2.4-2

References

https://github.com/openwrt/luci/security/advisories/GHSA-...
x_refsource_CONFIRM
https://github.com/openwrt/luci/pull/8705
x_refsource_MISC
https://github.com/openwrt/luci/commit/9ccd99b5898457e5ef...
x_refsource_MISC

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.