# CVE-2026-90606: Totolink A3002MU buffer overflow in IPv6 setup

Source: https://junglewise.ai/threats/cve-2026-90606-totolink-a3002mu-buffer-overflow-in-ipv6-setup  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-14. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-90606 · Severity: critical · CVSS 9.9 · Published 2026-09-14

Totolink A3002MU is a wireless router used to provide internet connectivity for home and small office networks. A buffer overflow vulnerability in the router's web management interface allows a remote attacker to crash the web service by sending a specially crafted request with an excessively long IPv6 parameter, causing a denial of service and making the router inaccessible to administrators until reboot.

Technologies: [TOTOLINK A3002MU](https://junglewise.ai/threats/technologies/a3002mu). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-90606 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90606 being exploited in the wild.

**How severe is CVE-2026-90606?** Critical severity, with a CVSS score of 9.9, published 14 September 2026.

**Which products and versions are affected?** TOTOLINK A3002MU Hh-B20211125.1046.

**Is there a fix for CVE-2026-90606?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-90606 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-90606?** Check whether you run TOTOLINK A3002MU at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A buffer overflow vulnerability exists in the formIpv6Setup function of the Boa web server component (/boafrm/formIpv6Setup endpoint) in Totolink A3002MU firmware Hh-B20211125.1046. The vulnerability is triggered when the static_ipv6 parameter is processed without proper length validation, allowing an attacker to overwrite adjacent memory. The attack is network-reachable and requires only network access to the router's web interface (no authentication bypass needed if the interface is accessible). A remote attacker can send a crafted POST request with an oversized static_ipv6 value to crash the Boa process, resulting in denial of service. The vulnerability has been publicly disclosed with proof-of-concept code available.

## Affected products

- Totolink A3002MU Hh-B20211125.1046

## Timeline

- 2026-09-14: disclosed: Vulnerability publicly disclosed with proof-of-concept
- 2026-09-14: other: CVE-2026-90606 assigned

## References

- [https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/ToTolink/A3002MU/bof-formIpv6Setup.md](https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/ToTolink/A3002MU/bof-formIpv6Setup.md)
- [https://vuldb.com/cve/CVE-2026-90606](https://vuldb.com/cve/CVE-2026-90606)

## Related threats

- [Totolink A3002MU path traversal in file upload handler](https://junglewise.ai/threats/cve-2026-105286-a-vulnerability-was-detected-in-totolink-a3002mu-1-0-0-b20230403)
- [Totolink A3002MU stack buffer overflow in QoS handler](https://junglewise.ai/threats/cve-2026-105285-a-security-vulnerability-has-been-detected-in-totolink-a3002mu-1)
- [Totolink A3002MU authentication bypass in bin/boa](https://junglewise.ai/threats/cve-2026-105284-a-weakness-has-been-identified-in-totolink-a3002mu-1-0-0)
- [Totolink A3002MU command injection in formWsc](https://junglewise.ai/threats/cve-2026-93742-a-weakness-has-been-identified-in-totolink-a3002mu-hh-b20211125)
- [Totolink A3002MU buffer overflow in formWlWds](https://junglewise.ai/threats/cve-2026-93741-a-security-flaw-has-been-discovered-in-totolink-a3002mu-hh)