# CVE-2026-95104: Buffalo WSR-300HP and WEX-G300 stack-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-95104-stack-based-buffer-overflow-vulnerability-exists-in-buffalo-wi-fi  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-28. Updated: 2026-09-28  
License: CC BY 4.0 with a link back

CVE-2026-95104 · Severity: high · CVSS 7.5 · Published 2026-09-28

Buffalo Wi-Fi router and repeater products contain a stack-based buffer overflow in their web configuration interface. An unauthenticated attacker can send a specially crafted HTTP request over the network to crash the device and cause a denial-of-service condition, disrupting network connectivity for users relying on these devices.

Vendors: [Buffalo](https://junglewise.ai/threats/vendors/buffalo).

## Quick answers

**Is CVE-2026-95104 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-95104 being exploited in the wild.

**How severe is CVE-2026-95104?** High severity, with a CVSS score of 7.5, published 28 September 2026.

**Which products and versions are affected?** Buffalo WEX-G300 prior to Ver.1.71; Buffalo WSR-300HP prior to Ver.2.55.

**Is there a fix for CVE-2026-95104?** A patch was published on 2026-08-25: WSR-300HP firmware Ver.2.55 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-95104 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-95104?** Check whether you run Buffalo WEX-G300 or Buffalo WSR-300HP 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 (CWE-121) exists in the web configuration interface of affected Buffalo Wi-Fi products. The vulnerability is triggered by a non-authenticated crafted HTTP request and can be exploited remotely via network access, causing a denial-of-service condition. Patches have been released with firmware versions 2.55 for WSR-300HP and 1.71 for WEX-G300.

## Affected products

- Buffalo WSR-300HP prior to Ver.2.55
- Buffalo WEX-G300 prior to Ver.1.71

## Timeline

- 2026-09-28: disclosed
- 2026-08-25: patched: WSR-300HP firmware Ver.2.55 released
- 2026-09-03: patched: WEX-G300 firmware Ver.1.71 released

## References

- [https://jvn.jp/en/vu/JVNVU94863997/](https://jvn.jp/en/vu/JVNVU94863997/)
- [https://www.buffalo.jp/news/detail/20260928-01.html](https://www.buffalo.jp/news/detail/20260928-01.html)

## Related threats

- [BUFFALO Wi-Fi products OS command injection](https://junglewise.ai/threats/cve-2026-86530-buffalo-wi-fi-products-handle-some-web-form-input-improperly-to)