CVE-2026-55159Public exploitNetwork attack vectorHinoki check available

Root command execution via newline-injected cron entries

Published Sep 21, 2026 · Updated Sep 21, 2026

CRLF injection in OpenWrt luci-app-adblock-fast before 1.2.4-2 allows remote authenticated users to execute commands as root. The luci.adblock-fast.setCronEntry RPC appends its entry argument to /etc/crontabs/root without rejecting carriage returns or line feeds, turning one logical value into multiple root cron lines. Exploitation requires the component's write ACL; injected commands run as UID 0 when cron processes the added line and persist until that line is removed.

CVSS severity8.8
High
EPSS probability0.49%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

CRLF injection in OpenWrt luci-app-adblock-fast before 1.2.4-2 allows remote authenticated users to execute commands as root. The luci.adblock-fast.setCronEntry RPC appends its entry argument to /etc/crontabs/root without rejecting carriage returns or line feeds, turning one logical value into multiple root cron lines. Exploitation requires the component's write ACL; injected commands run as UID 0 when cron processes the added line and persist until that line is removed.

The record

CVE
CVE-2026-55159
Published
Sep 21, 2026
Updated
Sep 21, 2026
Vendor
OpenWrt
Product
luci-app-adblock-fast
Classifications
CWE-93, T1053.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.2.4-2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenWrt · luci-app-adblock-fastversion=< 1.2.4-2

Published CVSS scores

8.8GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
T1053.003Scheduled Task/Job: Cron

Public exploit references

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Technologies

Your stack

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