# CVE-2026-9531: Totolink CA750-PoE command injection in setUpgradeUboot

Source: https://junglewise.ai/threats/cve-2026-9531-totolink-ca750-poe-command-injection-in-setupgradeuboot  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-26. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9531 · Severity: medium · CVSS 6.3 · Published 2026-05-26

A vulnerability exists in the Totolink CA750-PoE router, a device used to provide wireless networking and Power-over-Ethernet capabilities. An attacker can exploit this flaw to take full control of the device by executing unauthorized system commands. This could lead to the interception of network traffic, disruption of internet services, or use of the device as a foothold for further attacks on the internal network.

Technologies: [TOTOLINK CA750-PoE](https://junglewise.ai/threats/technologies/ca750-poe). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-9531 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9531 being exploited in the wild.

**How severe is CVE-2026-9531?** Medium severity, with a CVSS score of 6.3, published 26 May 2026.

**Which products and versions are affected?** TOTOLINK CA750-PoE 6.2c.510.

**Is there a fix for CVE-2026-9531?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-9531 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-9531?** Check whether you run TOTOLINK CA750-PoE at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An OS command injection vulnerability exists in the Totolink CA750-PoE firmware version 6.2c.510. The flaw is located within the 'setUpgradeUboot' function in the '/cgi-bin/cstecgi.cgi' handler, specifically due to improper neutralization of the 'FileName' argument. A remote attacker with low privileges can send a crafted POST request containing shell metacharacters (e.g., backticks) in the FileName parameter to execute arbitrary OS commands on the underlying system. Public exploit code demonstrates that this can be used to start a telnet daemon and gain root shell access.

## Affected products

- Totolink CA750-PoE 6.2c.510

## Timeline

- 2026-05-26: disclosed: Vulnerability details and PoC published on GitHub
- 2026-05-26: advisory: NVD/VulDB advisory published

## References

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

## Related threats

- [Totolink CA750-PoE command injection in setWiFiWpsConfig](https://junglewise.ai/threats/cve-2026-9534-totolink-ca750-poe-command-injection-in-setwifiwpsconfig)
- [Totolink CA750-PoE command injection in recvUpgradeNewFw](https://junglewise.ai/threats/cve-2026-9533-totolink-ca750-poe-command-injection-in-recvupgradenewfw)
- [Totolink CA750-PoE command injection in setUploadUserData](https://junglewise.ai/threats/cve-2026-9532-totolink-ca750-poe-command-injection-in-setuploaduserdata)
- [Totolink CA750-PoE command injection in setUnloadUserData](https://junglewise.ai/threats/cve-2026-9515-totolink-ca750-poe-command-injection-in-setunloaduserdata)
- [TOTOLink CA750-PoE OS command injection in setNetworkDiag](https://junglewise.ai/threats/cve-2026-9514-totolink-ca750-poe-os-command-injection-in-setnetworkdiag)