# CVE-2026-5350: Trendnet TEW-657BRM stack overflow in setup.cgi

Source: https://junglewise.ai/threats/cve-2026-5350-trendnet-tew-657brm-stack-overflow-in-setup-cgi  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-02. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-5350 · Severity: high · CVSS 8.8 · Published 2026-04-02

A security vulnerability exists in the Trendnet TEW-657BRM wireless router, a device used to provide internet connectivity and networking for homes and small offices. An attacker could exploit this flaw to take control of the device or cause it to crash, potentially leading to unauthorized access to the network or a total loss of internet service. Because this product reached its end-of-life in 2011, the manufacturer will not be releasing a security patch, and users are advised to replace the hardware.

Technologies: [TRENDnet Tew-657brm](https://junglewise.ai/threats/technologies/tew-657brm), [TRENDnet Tew-657brm Firmware](https://junglewise.ai/threats/technologies/tew-657brm-firmware). Vendors: [TRENDnet](https://junglewise.ai/threats/vendors/trendnet).

## Quick answers

**Is CVE-2026-5350 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5350 being exploited in the wild.

**How severe is CVE-2026-5350?** High severity, with a CVSS score of 8.8, published 2 April 2026.

**Which products and versions are affected?** TRENDnet Tew-657brm 1.00.1.

**Is there a fix for CVE-2026-5350?** 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-2026-5350 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-5350?** Check whether you run TRENDnet Tew-657brm or TRENDnet Tew-657brm Firmware 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

A stack-based buffer overflow vulnerability exists in the 'update_pcdb' function within the '/setup.cgi' file of Trendnet TEW-657BRM firmware version 1.00.1. The root cause is the unsafe use of the 'strcpy' function when processing the 'mac_pc_dba' HTTP POST parameter, which fails to validate the length of user-supplied input before copying it to a fixed-size stack buffer. A remote attacker with low-level authentication can exploit this by sending a specially crafted POST request to trigger the overflow. This can lead to arbitrary code execution or a device crash (DoS). The vendor has stated the product is end-of-life (EOL) as of 2011 and no patch will be provided.

## Affected products

- Trendnet TEW-657BRM 1.00.1

## Timeline

- 2011-06-23: other: Product reached End-of-Life (EOL) status
- 2026-04-02: disclosed: Initial disclosure and public release of exploit code
- 2026-04-02: advisory

## References

- [https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/update_pcdb.md](https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/update_pcdb.md)
- [https://vuldb.com/submit/781567](https://vuldb.com/submit/781567)
- [https://vuldb.com/vuln/354703](https://vuldb.com/vuln/354703)
- [https://vuldb.com/vuln/354703/cti](https://vuldb.com/vuln/354703/cti)

## Related threats

- [Trendnet TEW-657BRM command injection in setup.cgi](https://junglewise.ai/threats/cve-2026-5355-trendnet-tew-657brm-command-injection-in-setup-cgi)
- [Trendnet TEW-657BRM command injection in setup.cgi](https://junglewise.ai/threats/cve-2026-5354-trendnet-tew-657brm-command-injection-in-setup-cgi)
- [Trendnet TEW-657BRM command injection in setup.cgi](https://junglewise.ai/threats/cve-2026-5353-trendnet-tew-657brm-command-injection-in-setup-cgi)
- [Trendnet TEW-657BRM OS command injection in setup.cgi](https://junglewise.ai/threats/cve-2026-5352-trendnet-tew-657brm-os-command-injection-in-setup-cgi)
- [Trendnet TEW-657BRM OS command injection in setup.cgi](https://junglewise.ai/threats/cve-2026-5351-trendnet-tew-657brm-os-command-injection-in-setup-cgi)