Tenda AC5: Stack-based buffer overflow in Wi-Fi handler (/goform/setWifi)
Summary
The Wi-Fi handler of the web management interface on Tenda AC5 routers does not check the length of the wifiPwd parameter in /goform/setWifi before copying it into a fixed-size stack buffer. An attacker with a valid administrator session can send an oversized value to corrupt memory. A public proof of concept shows control of the instruction pointer and corruption of stored Wi-Fi settings that can survive reboots, so remote code execution is considered likely but is not confirmed.
Affected
- Tenda AC5 v3, firmware 02.03.01.111_multi (as listed by the CNA)
Fixed in
Unknown. No vendor fix or fixed version has been found for this CVE.
Workaround
- Disable WAN-side administration on the device.
- Block inbound access to the HTTP management port with a firewall and separate the management interface from user networks.
- Restrict who can log in to the web interface.
Exploitation
- A public proof of concept is available.
- CISA SSVC lists exploitation as poc and automatable as no.
- No confirmed active exploitation has been found.
Our recommendation
- Check whether the web management interface of affected Tenda AC5 devices is reachable from the internet and close that exposure.
- Apply the workarounds above until Tenda publishes a fixed firmware.
- Monitor devices for unexplained reboots or crashes of the web service.
- Replace the device if no fix is released and the exposure cannot be removed.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Tenda AC5v3 goform/setWifi wifiPwd Stack-Based Buffer Overflow (GitHub) github.com
- VulDB CVE-2026-105778 vuldb.com
- VulDB entry 413811 vuldb.com
- SentinelOne vulnerability database CVE-2026-105778 www.sentinelone.com
- Tenda AC5 v3 product support page www.tendacn.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 09:21.
Original description (NVD)
A vulnerability has been found in Tenda AC5 02.03.01.111_multi. Affected by this issue is some unknown functionality of the file /goform/setWifi of the component Wifi Handler. Such manipulation of the argument wifiPwd leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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