# CVE-2026-36822: Tenda W20E buffer overflow in formDelStaState

Source: https://junglewise.ai/threats/cve-2026-36822-tenda-w20e-buffer-overflow-in-formdelstastate  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-36822 · Severity: info · Published 2026-06-09

The Tenda W20E enterprise-grade router is vulnerable to a security flaw that can be triggered by sending a specifically formatted web request. An attacker can exploit this to crash the device, leading to a total loss of internet connectivity and network services for all connected users. This results in a denial-of-service condition that requires a manual restart or intervention to restore operations.

Technologies: [Tenda W20E](https://junglewise.ai/threats/technologies/w20e). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-36822 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36822 being exploited in the wild.

**How severe is CVE-2026-36822?** Informational severity, published 9 June 2026.

**Which products and versions are affected?** Tenda W20E v15.11.0.6.

**Is there a fix for CVE-2026-36822?** 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-2026-36822 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36822?** Check whether you run Tenda W20E 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 Tenda W20E v15.11.0.6 firmware within the 'formDelStaState' function. The vulnerability is triggered when the 'macAddr' HTTP parameter, retrieved via 'websGetVar', is passed to 'init_wl_policy_list'. Inside this function, a 'memcpy' operation uses a source string derived from 'strtok' without adequate bounds checking, copying up to 0x20 bytes into a destination buffer that can be overrun if the input string (e.g., a long sequence of characters followed by a comma) exceeds expected lengths. A remote attacker can exploit this by sending a crafted HTTP request to the 'delStaState' action, resulting in a process crash or device instability (Denial of Service).

## Affected products

- Tenda W20E v15.11.0.6

## Timeline

- 2026-03-19: other: CVE request submitted to MITRE
- 2026-06-06: disclosed: Public disclosure
- 2026-06-09: advisory: NVD published date

## References

- [https://github.com/xhh0124/SemVulLLM/tree/main/W20E/formDelStaState](https://github.com/xhh0124/SemVulLLM/tree/main/W20E/formDelStaState)

## Related threats

- [Tenda W20E stack buffer overflow in formDelWebAuthWhiteUser](https://junglewise.ai/threats/cve-2026-90689-tenda-w20e-stack-buffer-overflow-in-formdelwebauthwhiteuser)
- [Tenda W20E stack buffer overflow in formIPMacBindAdd](https://junglewise.ai/threats/cve-2026-90688-tenda-w20e-stack-buffer-overflow-in-formipmacbindadd)
- [Tenda W20E buffer overflow in formAddWebAuthUser](https://junglewise.ai/threats/cve-2026-36823-tenda-w20e-buffer-overflow-in-formaddwebauthuser)
- [Tenda W20E buffer overflow in formCropAndSetWewifiPic](https://junglewise.ai/threats/cve-2026-36821-tenda-w20e-buffer-overflow-in-formcropandsetwewifipic)
- [Tenda W20E buffer overflow in formAddWebAuthWhiteUser](https://junglewise.ai/threats/cve-2026-36820-tenda-w20e-buffer-overflow-in-formaddwebauthwhiteuser)