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PatchSiren cyber security CVE debrief

CVE-2026-61876 openwrt CVE debrief

The CVE record indicates that LuCI versions have a vulnerability where DHCPv6 lease hostnames are not properly encoded before being rendered in status tables. This allows adjacent network attackers to inject HTML markup by sending a DHCPv6 Client FQDN containing script tags. These script tags can execute in the administrator's browser when viewing DHCP lease pages. The vulnerability is critical, with a CVSS score of 9.4, emphasizing the need for immediate attention and remediation.

Vendor
openwrt
Product
luci
CVSS
CRITICAL 9.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-12
Original CVE updated
2026-07-12
Advisory published
2026-07-12
Advisory updated
2026-07-12

Who should care

Administrators and users of LuCI, especially those managing network configurations and DHCP leases, should be aware of this vulnerability. It is crucial for them to ensure their systems are updated to prevent potential attacks. Additionally, security teams and vulnerability management personnel should prioritize patching and monitoring to mitigate the risk of exploitation.

Technical summary

The vulnerability exists due to improper encoding of DHCPv6 lease hostnames in LuCI status tables. Attackers can exploit this by sending crafted DHCPv6 Client FQDNs that include script tags. When an administrator views the DHCP lease pages, these script tags can execute, potentially leading to unauthorized actions or information disclosure. The issue arises from inadequate input validation and sanitization of user-supplied hostname data, allowing for cross-site scripting (XSS) attacks. To mitigate, ensure that all user-supplied input is properly encoded and validated.

Defensive priority

High

Recommended defensive actions

  • Update LuCI to the latest version that addresses this vulnerability.
  • Implement network monitoring to detect suspicious DHCPv6 traffic.
  • Restrict access to DHCP lease pages to authorized personnel only.
  • Regularly review and update system configurations to ensure security patches are applied.
  • Conduct a thorough review of existing DHCPv6 lease hostnames for potential malicious content.
  • Implement additional security measures such as Web Application Firewalls (WAFs) to detect and prevent XSS attacks.
  • Perform regular security audits to identify and address potential vulnerabilities in network configurations.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability. However, further details about the affected versions and patches are not provided in the given source corpus. It is recommended to check the official LuCI repository or vendor advisories for specific remediation steps. The vulnerability highlights the importance of proper input validation and sanitization in web applications, particularly those managing network configurations.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-12T12:16:46.400Z and has not been modified since then.