# CVE-2026-82616: TOTOLINK NR1800X stack-based buffer overflow in setUploadSetting

Source: https://junglewise.ai/threats/cve-2026-82616-totolink-nr1800x-stack-based-buffer-overflow-in-setuploadsetting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-31. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-82616 · Severity: critical · CVSS 9.9 · Published 2026-08-31

TOTOLINK NR1800X is a network router used in home and small business environments. A stack-based buffer overflow vulnerability in the web administration interface allows an attacker to send a specially crafted request with an oversized filename parameter, potentially leading to remote code execution and complete compromise of the device. The exploit has been publicly disclosed and proof-of-concept code is available.

Technologies: [TOTOLINK Nr1800x](https://junglewise.ai/threats/technologies/nr1800x). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-82616 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-82616 being exploited in the wild.

**How severe is CVE-2026-82616?** Critical severity, with a CVSS score of 9.9, published 31 August 2026.

**Which products and versions are affected?** TOTOLINK Nr1800x 9.1.0u.6681_B20230703.

**Is there a fix for CVE-2026-82616?** 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-2026-82616 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-82616?** Check whether you run TOTOLINK Nr1800x 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 stack-based buffer overflow exists in the setUploadSetting function of the /cgi-bin/cstecgi.cgi endpoint. The vulnerability is triggered by insufficient bounds checking on the FileName parameter, which allows an attacker to overwrite stack memory by providing an excessively long filename. The attack is remotely exploitable without authentication requirements and can lead to arbitrary code execution with device privileges. A public proof-of-concept has been released, increasing the risk of active exploitation.

## Affected products

- TOTOLINK NR1800X 9.1.0u.6681_B20230703

## Timeline

- 2026-08-31: disclosed
- other: Public exploit proof-of-concept released

## References

- [https://github.com/lxiansheng488-bit/-/blob/main/TOTOlink/totolink%20setUploadSetting%E6%A0%88%E6%BA%A2%E5%87%BA.pdf](https://github.com/lxiansheng488-bit/-/blob/main/TOTOlink/totolink%20setUploadSetting%E6%A0%88%E6%BA%A2%E5%87%BA.pdf)
- [https://vuldb.com/cve/CVE-2026-82616](https://vuldb.com/cve/CVE-2026-82616)

## Related threats

- [TOTOLINK NR1800X command injection in setUssd](https://junglewise.ai/threats/cve-2026-82597-totolink-nr1800x-command-injection-in-setussd)
- [Totolink NR1800X stack overflow in Form_Logout](https://junglewise.ai/threats/cve-2026-15701-totolink-nr1800x-stack-overflow-in-form-logout)
- [ToToLink Routers stack buffer overflow in cstecgi.cgi](https://junglewise.ai/threats/cve-2025-60688-totolink-routers-stack-buffer-overflow-in-cstecgi-cgi)
- [ToToLink Routers stack buffer overflow in cstecgi.cgi](https://junglewise.ai/threats/cve-2025-60684-totolink-routers-stack-buffer-overflow-in-cstecgi-cgi)