# CVE-2026-36958: U-SPEED N300 resource exhaustion DoS in Boa HTTP server

Source: https://junglewise.ai/threats/cve-2026-36958-u-speed-n300-resource-exhaustion-dos-in-boa-http-server  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-30. Updated: 2026-07-05  
License: CC BY 4.0 with a link back

CVE-2026-36958 · Severity: high · CVSS 7.5 · Published 2026-04-30

A denial-of-service vulnerability affects the U-SPEED N300 wireless router, a device used to provide internet connectivity in home or small office environments. By flooding the device with web requests, an attacker can crash the management interface, making it impossible for administrators to change settings or monitor the network. In some cases, this may disrupt general routing services and require a physical manual reboot to restore the device to a working state.

Vendors: [U-SPEED](https://junglewise.ai/threats/vendors/u-speed).

## Quick answers

**Is CVE-2026-36958 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-36958 being exploited in the wild.

**How severe is CVE-2026-36958?** High severity, with a CVSS score of 7.5, published 30 April 2026.

**Which products and versions are affected?** U-SPEED N300 1.0.0.

**Is there a fix for CVE-2026-36958?** 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-2026-36958 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-36958?** Check whether you run U-SPEED N300 or U-SPEED N300 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 denial-of-service (DoS) vulnerability exists in the U-SPEED N300 router (firmware V1.0.0) due to uncontrolled resource consumption (CWE-400) in the embedded Boa HTTP server. The vulnerability is triggered by sending a high volume of concurrent HTTP requests to arbitrary or non-existent endpoints on the web management interface. This resource exhaustion causes the web server to become unresponsive and may impact broader routing functionality. The attack can be launched remotely over the network without authentication or user interaction. A manual reboot is typically required to restore service, as the device lacks sufficient rate limiting or automated recovery mechanisms for this condition.

## Affected products

- U-SPEED N300 1.0.0

## Timeline

- 2026-04-29: disclosed: Vulnerability discovered and reported to MITRE
- 2026-04-30: advisory: NVD published the CVE record

## References

- [https://github.com/kirubel-cve/CVE-2026-36958](https://github.com/kirubel-cve/CVE-2026-36958)

## Related threats

- [U-SPEED N300 missing rate limiting in /api/login](https://junglewise.ai/threats/cve-2026-36959-u-speed-n300-missing-rate-limiting-in-api-login)