# CVE-2026-5349: Trendnet TEW-657BRM stack overflow in setup.cgi

Source: https://junglewise.ai/threats/cve-2026-5349-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-2026-5349 · Severity: high · CVSS 8.8 · Published 2026-04-02

A security vulnerability has been identified in the Trendnet TEW-657BRM, a wireless router used for home and small office networking. An attacker could exploit this flaw to gain full control over the device, potentially leading to data interception or a complete service outage. However, the manufacturer has stated that this product reached its end-of-life in 2011 and will not receive a security patch.

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-2026-5349 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5349 being exploited in the wild.

**How severe is CVE-2026-5349?** 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-2026-5349?** 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-2026-5349 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-5349?** 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 exists in the 'add_apcdb' function within the '/setup.cgi' file of Trendnet TEW-657BRM firmware version 1.00.1. The vulnerability is caused by the improper use of the 'strcpy' function when processing the 'mac_pc_dba' HTTP POST parameter, which allows an attacker to overwrite the stack. A remote attacker with low privileges (authenticated) can exploit this by sending a specially crafted request to the device. Successful exploitation can lead to remote code execution (RCE) or a device crash. No patch is available as the product is end-of-life (EOL).

## Affected products

- Trendnet TEW-657BRM 1.00.1

## Timeline

- 2011-06-23: other: Product reached End-of-Life (EOL) status
- 2026-04-02: disclosed: Vulnerability publicly disclosed
- 2026-04-02: advisory: NVD advisory published

## References

- [https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/add_apcdb.md](https://github.com/panda666-888/vuls/blob/main/trendnet/tew-657brm/add_apcdb.md)
- [https://vuldb.com/submit/781563](https://vuldb.com/submit/781563)
- [https://vuldb.com/vuln/354702](https://vuldb.com/vuln/354702)
- [https://vuldb.com/vuln/354702/cti](https://vuldb.com/vuln/354702/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)