CVE-2026-55159: openwrt luci-app-adblock-fast · CRLF Injection
Affects openwrt luci-app-adblock-fastSource CVE Database V5
Not known to be exploited · CVSS 8.8 High : upgrade to 1.2.4-2 soon.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.2.4-2
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade luci-app-adblock-fast and openwrt/luci-app-adblock-fast to 1.2.4-2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| openwrtluci-app-adblock-fast | Affected
| Fixed in
|
GitHubopenwrt/luci-app-adblock-fastpkg:github/openwrt/luci-app-adblock-fastOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade luci-app-adblock-fast to version 1.2.4-2 or later, where this vulnerability is fixed. Until the upgrade, restrict write ACL permissions to trusted users only. No other mitigations are specified by the vendor.
Description
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.
References
- github.com/openwrt/luci/security/advisories/GHSA-ggpf-xrph-wg5v (opens in a new tab)
- github.com/openwrt/luci/pull/8705 (opens in a new tab)
- github.com/openwrt/luci/commit/9ccd99b5898457e5ef39dc21aea226d7fb6e5c7e (opens in a new tab)
- github.com/openwrt/luci/commit/f67461fd0255bf992b2b559c22ec288067f2f9da (opens in a new tab)