# CVE-2026-90608: Totolink A3002MU buffer overflow in formPortFw

Source: https://junglewise.ai/threats/cve-2026-90608-totolink-a3002mu-buffer-overflow-in-formportfw  
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-2026-90608 · Severity: critical · CVSS 9.9 · Published 2026-09-14

The Totolink A3002MU is a wireless router used to provide internet connectivity in homes and small businesses. A buffer overflow vulnerability in its web management interface allows attackers to send a specially crafted HTTP request that crashes the web service, preventing access to router configuration. This denial-of-service attack requires network access to the router's management port but could potentially enable code execution.

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

## Quick answers

**Is CVE-2026-90608 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90608 being exploited in the wild.

**How severe is CVE-2026-90608?** 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-2026-90608?** 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-2026-90608 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-90608?** 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 boa web server's formPortFw function within the Totolink A3002MU router firmware. The vulnerability stems from unsafe string-copy logic in the service_type parameter handler, which fails to enforce proper length boundaries before copying user input into a fixed-size buffer. An unauthenticated remote attacker can send a POST request to /boafrm/formPortFw with an excessively long service_type parameter to trigger the overflow, overwriting adjacent memory and crashing the boa process. The attack results in denial of service (web interface unavailability), and successful exploitation could potentially lead to arbitrary code execution. The exploit details have been publicly disclosed.

## Affected products

- Totolink A3002MU Hh-B20211125.1046

## Timeline

- 2026-09-14: disclosed
- other: Exploit published on GitHub (cuicuishark-sheep-fishIOT repository)

## References

- [https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/ToTolink/A3002MU/bof-formPortFw.md](https://github.com/SunnyYANGyaya/cuicuishark-sheep-fishIOT/blob/main/ToTolink/A3002MU/bof-formPortFw.md)
- [https://vuldb.com/cve/CVE-2026-90608](https://vuldb.com/cve/CVE-2026-90608)

## 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)