# CVE-2026-42023: Totolink X2000R stack buffer overflow in formIpv6Setup

Source: https://junglewise.ai/threats/cve-2026-42023-multiple-stack-based-buffer-overflow-vulnerabilities-exist-in-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-42023 · Severity: critical · CVSS 9.1 · Published 2026-10-20

The Totolink X2000R is a budget home router that manages network configuration including IPv6 settings. Multiple stack buffer overflow flaws in the network configuration interface allow authenticated attackers to execute arbitrary code by sending specially crafted HTTP requests, potentially taking complete control of the router.

Technologies: [TOTOLINK X2000r](https://junglewise.ai/threats/technologies/x2000r). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-42023 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42023 being exploited in the wild.

**How severe is CVE-2026-42023?** Critical severity, with a CVSS score of 9.1, published 20 October 2026.

**Which products and versions are affected?** TOTOLINK X2000r TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327.

**Is there a fix for CVE-2026-42023?** 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-2026-42023 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-42023?** Check whether you run TOTOLINK X2000r 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

Stack-based buffer overflow vulnerabilities (CWE-121) exist in the formIpv6Setup function of the boa web server on Totolink X2000R, affecting parameters including static_dns1, static_dns2, and static_ipv6, which are copied to the stack without bounds checking. An authenticated attacker can trigger arbitrary code execution via a specially crafted HTTP request, as confirmed by crash data showing controlled return address hijacking (pc = 0x42424242).

## Affected products

- Totolink X2000R TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327

## Timeline

- 2026-10-20: disclosed

## References

- [https://talosintelligence.com/vulnerability_reports/TALOS-2026-2395](https://talosintelligence.com/vulnerability_reports/TALOS-2026-2395)

## Related threats

- [TOTOLINK X2000R stack-based buffer overflow in formTR069Config](https://junglewise.ai/threats/cve-2026-9869-a-stack-based-buffer-overflow-vulnerability-exists-in-the-boa)
- [Totolink X2000R arbitrary file write in boa formUploadFile](https://junglewise.ai/threats/cve-2026-9827-a-arbitrary-file-write-vulnerability-exists-in-the-boa)
- [Totolink X2000R stack-based buffer overflow in boa formUploadFile](https://junglewise.ai/threats/cve-2026-9817-a-stack-based-buffer-overflow-vulnerability-exists-in-the-boa)
- [Totolink X2000R OS command injection in formWizard](https://junglewise.ai/threats/cve-2026-9814-an-os-command-injection-vulnerability-exists-in-the-boa-formwizard)
- [TOTOLINK X2000R stack-based buffer overflow in boa formFilter](https://junglewise.ai/threats/cve-2026-9660-multiple-exploitable-stack-based-buffer-overflow-vulnerabilities)