# CVE-2026-5604: Tenda CH22 stack overflow in formCertLocalPrecreate

Source: https://junglewise.ai/threats/cve-2026-5604-tenda-ch22-stack-overflow-in-formcertlocalprecreate  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-05. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-5604 · Severity: high · CVSS 8.8 · Published 2026-04-05

A security vulnerability exists in the Tenda CH22, a networking device. An attacker can exploit this flaw to crash the device or potentially take full control of it by sending a specially crafted web request. This could lead to a complete loss of service or unauthorized access to the network traffic managed by 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-2026-5604 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-5604 being exploited in the wild.

**How severe is CVE-2026-5604?** High severity, with a CVSS score of 8.8, published 5 April 2026.

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

**Is there a fix for CVE-2026-5604?** 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-2026-5604 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-5604?** 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 'formCertLocalPrecreate' function within the '/goform/CertLocalPrecreate' endpoint of Tenda CH22 firmware version 1.0.0.1. The root cause is the unsafe use of the 'sprintf' function, which processes the user-supplied 'standard' parameter without adequate length validation, allowing the stack-based buffer 's' to be overwritten. A remote attacker with low privileges can exploit this by sending a crafted POST request. Successful exploitation can lead to a Denial of Service (DoS) or Remote Code Execution (RCE). A public Proof of Concept (PoC) has been released.

## Affected products

- Tenda CH22 1.0.0.1

## Timeline

- 2026-04-05: disclosed
- 2026-04-05: advisory

## References

- [https://github.com/Litengzheng/vuldb_new/blob/main/CH22/vul_52/README.md](https://github.com/Litengzheng/vuldb_new/blob/main/CH22/vul_52/README.md)
- [https://vuldb.com/submit/785032](https://vuldb.com/submit/785032)
- [https://vuldb.com/vuln/355396](https://vuldb.com/vuln/355396)
- [https://vuldb.com/vuln/355396/cti](https://vuldb.com/vuln/355396/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)