CVE-2026-55159

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (39th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.8Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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 v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
56
EG Risk 56/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 21, 2026

Last Modified

September 29, 2026

Advisory Details (4)

Auto-updated Sep 21, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
github_commit

commit f67461fd0255 (openwrt/luci)

Fix landed in openwrt/luci commit f67461fd0255 — awaiting tagged release

https://github.com/openwrt/luci/commit/f67461fd0255bf992b2b559c22ec288067f2f9da
github_commit

commit 9ccd99b58984 (openwrt/luci)

Fix landed in openwrt/luci commit 9ccd99b58984 — awaiting tagged release

https://github.com/openwrt/luci/commit/9ccd99b5898457e5ef39dc21aea226d7fb6e5c7e
github_pr

luci-app-adblock-fast: update to 1.2.4-2

Fix merged in openwrt/luci PR #8705 on 2026-06-15 — awaiting tagged release

https://github.com/openwrt/luci/pull/8705
github Patch Available🟡 PoC Available

luci-app-adblock-fast:Delegated `luci-app-adblock-fast` users can reach root command execution by injecting newline-separated cron entries · Advisory · openwrt/luci · GitHub

https://github.com/openwrt/luci/security/advisories/GHSA-ggpf-xrph-wg5v

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 16× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 18:48 UTCEG score recompute
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-03 05:39 UTCEG score recompute
  4. 2026-10-02 17:56 UTCEPSS rescore
  5. 2026-10-02 04:42 UTCEG score recompute
  6. 2026-10-01 19:50 UTCEPSS rescore
  7. 2026-09-30 15:16 UTCEG score recompute
  8. 2026-09-30 15:03 UTCEPSS rescore
  9. 2026-09-30 02:47 UTCEG score recompute
  10. 2026-09-29 15:22 UTCEPSS rescore
  11. 2026-09-29 14:19 UTCEG score recompute
  12. 2026-09-29 14:04 UTCEG score recompute
  13. 2026-09-29 01:22 UTCEG score recompute
  14. 2026-09-28 13:51 UTCEPSS rescore
  15. 2026-09-28 00:26 UTCEG score recompute
  16. 2026-09-27 13:48 UTCEPSS rescore
  17. 2026-09-26 23:30 UTCEG score recompute
  18. 2026-09-26 15:59 UTCEPSS rescore
  19. 2026-09-26 11:02 UTCEG score recompute
  20. 2026-09-24 21:37 UTCEG score recompute
  21. 2026-09-24 14:04 UTCEPSS rescore
  22. 2026-09-23 22:16 UTCEG score recompute
  23. 2026-09-23 17:54 UTCEPSS rescore
  24. 2026-09-22 21:19 UTCEG score recompute
  25. 2026-09-21 20:18 UTCEG score recompute
Show 2 more
  1. 2026-09-21 19:30 UTCEG score recompute
  2. 2026-09-21 19:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55159?
CVE-2026-55159 is a high vulnerability published on September 21, 2026. 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…
When was CVE-2026-55159 disclosed?
CVE-2026-55159 was first published on September 21, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55159 actively exploited?
CVE-2026-55159 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55159?
CVE-2026-55159 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55159?
A fix for CVE-2026-55159 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-55159

Explore →

Is Your Infrastructure Affected by CVE-2026-55159?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs