# CVE-2026-105778: Tenda AC5 stack-based buffer overflow in WiFi handler

Source: https://junglewise.ai/threats/cve-2026-105778-a-vulnerability-has-been-found-in-tenda-ac5-02-03-01-111-multi  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-105778 · Severity: critical · CVSS 9.9 · Published 2026-10-06

Tenda AC5 is a wireless router that manages home and small-office networks. An authenticated administrator can exploit a buffer overflow in the WiFi password parameter to corrupt memory, crash the device persistently (surviving reboots), or potentially execute arbitrary code. Recovery typically requires a factory reset.

Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-105778 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105778 being exploited in the wild.

**How severe is CVE-2026-105778?** Critical severity, with a CVSS score of 9.9, published 6 October 2026.

**Which products and versions are affected?** Tenda AC5 02.03.01.111_multi.

**Is there a fix for CVE-2026-105778?** 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-2026-105778 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-105778?** Check whether you run Tenda AC5 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 /goform/setWifi endpoint's wifiPwd parameter, which fails to validate input length before copying into a fixed-size buffer. An authenticated attacker can overwrite the program counter and corrupt NVRAM configuration memory, achieving instruction-pointer control and persistent denial-of-service. The vulnerability requires an authenticated admin session but enables complete device compromise.

## Affected products

- Tenda AC5 02.03.01.111_multi

## Timeline

- 2026-10-06: disclosed: Vulnerability disclosed publicly with proof of concept

## References

- [https://github.com/raisecnull/Tenda-AC5v3-BOF/blob/main/blog.md](https://github.com/raisecnull/Tenda-AC5v3-BOF/blob/main/blog.md)
- [https://vuldb.com/cve/CVE-2026-105778](https://vuldb.com/cve/CVE-2026-105778)