LuCI DHCPv6 Hostname Rendering Allows HTML Injection

LuCI versions fail to properly encode DHCPv6 lease hostnames before rendering in status tables, allowing adjacent network attackers to inject HTML markup. Attackers can send a DHCPv6 Client FQDN containing script tags that execute in the administrator's browser when viewing DHCP lease pages.

Casky was already ahead

This CVE exploits attack patterns that Casky's 322matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

LuCI, the web interface for OpenWrt routers and network devices, fails to properly encode DHCPv6 lease hostnames before displaying them in status tables. This stored cross-site scripting (XSS) vulnerability allows adjacent network attackers to inject malicious HTML and JavaScript by crafting DHCPv6 Client FQDN options containing script tags. When administrators view DHCP lease pages, the unencoded payload executes in their browser with administrative privileges, enabling session hijacking, credential theft, or further network compromise. The CVSS 8.8 score reflects the high impact on confidentiality and integrity, particularly in environments where network administrators manage critical infrastructure.

Casky's 322 matching skills leverage Claude's extended reasoning to detect the attack patterns mapped to TA0001 (Initial Access—specifically reconnaissance and network positioning by adjacent attackers) and TA0043 (Reconnaissance—DHCP probing and network enumeration). Practitioners using Casky would observe findings identifying: improper input validation on DHCPv6 hostname fields (CWE-79 root cause), absence of output encoding in template rendering, and detection of script injection payloads in DHCP traffic analysis. The platform would flag administrative UI interactions following DHCPv6 lease table access as suspicious behavioral patterns, correlating network-adjacent threat actors with DOM manipulation techniques and session context abuse—enabling defenders to prioritize patching and implement encoding controls before exploitation occurs.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

322 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-61876.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043

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