# CVE-2026-5204: Tenda CH22 stack buffer overflow in formWebTypeLibrary

Source: https://junglewise.ai/threats/cve-2026-5204-tenda-ch22-stack-buffer-overflow-in-formwebtypelibrary  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-31. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-5204 · Severity: high · CVSS 8.8 · Published 2026-03-31

A security vulnerability has been identified in the Tenda CH22, a networking device. An attacker could exploit this flaw to cause the device to crash or potentially take full control of it by sending a specially crafted web request. This could lead to a total loss of network availability or unauthorized access to data passing through the device.

Technologies: [Tenda CH22](https://junglewise.ai/threats/technologies/ch22), [Tenda Ch22 Firmware](https://junglewise.ai/threats/technologies/ch22-firmware). Vendors: [Tenda](https://junglewise.ai/threats/vendors/tenda).

## Quick answers

**Is CVE-2026-5204 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5204 being exploited in the wild.

**How severe is CVE-2026-5204?** High severity, with a CVSS score of 8.8, published 31 March 2026.

**Which products and versions are affected?** Tenda CH22 1.0.0.1.

**Is there a fix for CVE-2026-5204?** 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-2026-5204 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-5204?** Check whether you run Tenda CH22 or Tenda Ch22 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 Tenda CH22 firmware version 1.0.0.1. The flaw is located within the 'formWebTypeLibrary' function in the '/goform/webtypelibrary' component of the Parameter Handler. The root cause is an unsafe 'strcat' operation on the user-provided 'webSiteId' parameter without adequate length validation. A remote attacker with low privileges can trigger this overflow by sending a crafted POST request, potentially leading to remote code execution (RCE) or a denial of service (DoS) condition. A proof-of-concept exploit has been publicly disclosed.

## Affected products

- Tenda CH22 1.0.0.1

## Timeline

- 2026-03-31: disclosed: Vulnerability disclosed and CVE assigned
- 2026-03-31: advisory: Initial advisory published by VulDB

## References

- [https://github.com/Litengzheng/vuldb_new/blob/main/CH22/vul_49/README.md](https://github.com/Litengzheng/vuldb_new/blob/main/CH22/vul_49/README.md)
- [https://vuldb.com/submit/780209](https://vuldb.com/submit/780209)
- [https://vuldb.com/vuln/354332](https://vuldb.com/vuln/354332)
- [https://vuldb.com/vuln/354332/cti](https://vuldb.com/vuln/354332/cti)
- [https://www.tenda.com.cn/](https://www.tenda.com.cn/)

## Related threats

- [Tenda CH22 command injection in formexeCommand](https://junglewise.ai/threats/cve-2026-78141-tenda-ch22-command-injection-in-formexecommand)
- [Tenda CH22 command injection in editFileName](https://junglewise.ai/threats/cve-2026-78063-tenda-ch22-command-injection-in-editfilename)
- [Tenda CH22 command injection in formcreateFileName](https://junglewise.ai/threats/cve-2026-77031-tenda-ch22-command-injection-in-formcreatefilename)
- [Tenda CH22 buffer overflow in formCertListInfo](https://junglewise.ai/threats/cve-2026-15543-tenda-ch22-buffer-overflow-in-formcertlistinfo)
- [A vulnerability was detected in Tenda CH22 1.0.0.6(468). This issue affects the function R7WebsSecurityHandlerfunction…](https://junglewise.ai/threats/cve-2026-5962-a-vulnerability-was-detected-in-tenda-ch22-1-0-0-6-468-this-issue)