Ethical Hacking News
OpenWrt's DHCPv6 implementation has been found to be vulnerable to a critical issue that allows unauthenticated attackers to run code as root-level access. A recent update has addressed this flaw, but users are still at risk if they have not upgraded to the latest version of OpenWrt. Learn how to protect yourself against this vulnerability and stay safe online.
A critical vulnerability (CVE-2026-53921) has been found in OpenWrt's DHCPv6 implementation. The vulnerability allows an unauthenticated attacker to run code as root-level access on devices with OpenWrt. The issue exploits a stack overflow in the odhcpd service, which is responsible for handling DHCPv6 requests. The severity of this vulnerability is high, allowing potential attackers control over device settings and network connectivity. OpenWrt has released version 24.10.8 to address the issue, along with a separate pull request by Hacker House to fix other security weaknesses.
Critical vulnerabilities have been found in the OpenWrt operating system, specifically in its DHCPv6 implementation. According to recent reports, a critical issue has been identified that allows an unauthenticated attacker to run code as root-level access on devices equipped with OpenWrt.
The vulnerability, designated as CVE-2026-53921 and rated 9.8 on the Common Vulnerability Scoring System (CVSS) scale, exploits a stack overflow in the odhcpd service, which is responsible for handling DHCPv6 requests. The issue arises when an attacker sends a specially crafted DHCPv6 REQUEST packet to the server, causing it to overwrite a buffer and execute malicious code.
The severity of this vulnerability cannot be overstated, as it allows an unauthenticated attacker to access and manipulate device settings without needing to authenticate or have any prior knowledge of the system. This could potentially give an attacker control over the entire device, including its network connectivity and security features.
In response to this critical issue, OpenWrt has released version 24.10.8, which addresses the DHCPv6 stack overflow and a range of other remotely triggerable flaws in network services enabled by default. Additionally, a separate pull request has been submitted by Hacker House, an AI-assisted audit firm, that identified command-injection, path-traversal, and cross-site scripting (XSS) weaknesses in optional LuCI components.
The vulnerability is a significant concern for device owners and administrators, particularly those who have not yet upgraded to the latest version of OpenWrt. In this article, we will delve deeper into the details of this critical vulnerability and provide guidance on how users can protect themselves against it.
Related Information:
https://www.ethicalhackingnews.com/articles/Critical-OpenWrt-DHCPv6-Flaw-Leaves-Unauthenticated-Attackers-a-Backdoor-to-Root-Level-Access-ehn.shtml
https://thehackernews.com/2026/07/critical-openwrt-dhcpv6-flaw-could-let.html
https://nvd.nist.gov/vuln/detail/CVE-2026-53921
https://www.cvedetails.com/cve/CVE-2026-53921/
Published: Tue Jul 28 09:48:12 2026 by llama3.2 3B Q4_K_M
