CVE-2021-34346
QNAP
- Published
- 10 September 2021
- Last modified
- 17 June 2026
- CVSS
- 9.8 v3.1
- Severity
- critical
- EPSS
- 1.6% (74th pct)
- CISA KEV
- Not listed
- NVD status
- Modified
- Weaknesses
- CWE-787
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
A stack buffer overflow vulnerability has been reported to affect QNAP device running NVR Storage Expansion. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of NVR Storage Expansion: NVR Storage Expansion 1.0.6 ( 2021/08/03 ) and later
Exploitation
Not listed in the CISA Known Exploited Vulnerabilities catalogue as of 2026.09.04. That is an absence of confirmed public exploitation, not evidence that exploitation has not occurred. EPSS models a 1.6% probability of exploitation activity in the next 30 days.
Affected products
| Product | Vendor | Type | Versions named |
|---|---|---|---|
| NVR Storage Expansion | QNAP | Network video recorder | < 1.0.6 |
References
Vendor advisory and patch
- https://www.qnap.com/en/security-advisory/qsa-21-36
- https://www.qnap.com/en/security-advisory/qsa-21-36
Record assembled from NVD, CISA KEV 2026.09.04 and FIRST EPSS 2026-09-04. Affected products are those NVD's CPE configuration names that fall inside this site's scope; a CVE may affect products outside it.