CVE-2026-6988 Overview
CVE-2026-6988 is a buffer overflow vulnerability in the Tenda HG10 router running firmware version HG7_HG9_HG10re_300001138_en_xpon. The flaw resides in the formRoute function within /boaform/formRouting, part of the Boa web service. Attackers can exploit the issue by manipulating the nextHop parameter, triggering memory corruption in the embedded HTTP server. The vulnerability is remotely exploitable across the network and a public proof-of-concept exploit has been published, increasing exposure for affected deployments.
Critical Impact
Remote attackers with low privileges can trigger a buffer overflow in the Boa web service, leading to memory corruption and potential code execution on affected Tenda HG10 routers.
Affected Products
- Tenda HG10 router (hardware)
- Tenda HG10 firmware version 300001138 (HG7_HG9_HG10re_300001138_en_xpon)
- Boa Service component handling /boaform/formRouting
Discovery Timeline
- 2026-04-25 - CVE-2026-6988 published to NVD
- 2026-04-30 - Last updated in NVD database
Technical Details for CVE-2026-6988
Vulnerability Analysis
The vulnerability is classified as a buffer overflow [CWE-119] affecting the Boa HTTP server embedded in the Tenda HG10 firmware. The formRoute handler processes routing configuration requests submitted to /boaform/formRouting. The nextHop parameter, intended to carry the next-hop IP address for a route entry, is copied into a fixed-size stack or heap buffer without proper bounds enforcement.
When an attacker submits an oversized nextHop value, the copy operation writes beyond the allocated buffer. This corrupts adjacent memory and can overwrite saved return addresses or function pointers within the Boa worker process. Successful exploitation can lead to denial of service or arbitrary code execution within the router context.
Root Cause
The root cause is missing input length validation on the nextHop argument before it is copied into a bounded buffer inside formRoute. The Boa service operates with elevated privileges typical of embedded web administration daemons, amplifying impact on memory safety failures.
Attack Vector
Exploitation occurs over the network against the router's web management interface. The attacker requires low-privileged authenticated access to reach the formRouting endpoint. A crafted HTTP request containing an overlong nextHop value triggers the overflow. A public proof-of-concept is available in the GitHub PoC Repository, which lowers the barrier for opportunistic exploitation.
No verified exploitation code is reproduced here. Refer to the VulDB Vulnerability #359540 entry for additional technical context.
Detection Methods for CVE-2026-6988
Indicators of Compromise
- HTTP POST requests to /boaform/formRouting containing abnormally long nextHop parameter values
- Unexpected crashes, reboots, or restarts of the Boa web service on Tenda HG10 devices
- Outbound connections from the router to unfamiliar external hosts following administrative requests
Detection Strategies
- Inspect web server and reverse proxy logs for requests to /boaform/formRouting with parameter lengths exceeding typical IPv4 address sizes
- Deploy network intrusion detection signatures that flag oversized form fields sent to Boa-based embedded web servers
- Correlate router availability monitoring with administrative HTTP traffic to identify exploitation attempts causing service disruption
Monitoring Recommendations
- Forward router syslog and management-plane logs to a centralized analytics platform for retention and search
- Monitor authentication events on the router admin interface for brute-force or credential-stuffing patterns that precede exploitation
- Establish baseline traffic profiles for the router web UI and alert on anomalies in request size or frequency
How to Mitigate CVE-2026-6988
Immediate Actions Required
- Restrict access to the Tenda HG10 web administration interface so only trusted management hosts on isolated VLANs can reach /boaform/
- Disable remote WAN-side administration on affected devices to eliminate internet-exposed attack surface
- Rotate administrative credentials and enforce strong, unique passwords to limit low-privilege attacker reach
Patch Information
No vendor advisory or patch has been published for CVE-2026-6988 at the time of NVD publication. Operators should monitor the Tenda Official Website for firmware updates addressing the formRoute boundary check.
Workarounds
- Place affected routers behind a network firewall that blocks untrusted access to TCP ports serving the Boa web interface
- Replace end-of-life or unpatched Tenda HG10 devices with supported hardware if a vendor fix is not released
- Apply network segmentation so router management interfaces are unreachable from user and guest networks
# Example: restrict management access using an upstream firewall (iptables)
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -s <mgmt_subnet> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -s <mgmt_subnet> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
