Exploited. On CISA's list since 2022-03-25.
QNAP Helpdesk Improper Access Control Vulnerability
CVE-2020-2506 · QNAP Systems Helpdesk · Published 2021-02-03
How bad would it be?
9.8 out of 10
CVSS rates it critical: about as damaging as flaws get.
How likely is it to be used?
2.0%
Estimated chance of exploitation in the next 30 days, higher than 80% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 1659 days ago (2022-04-15).
What CISA says to do
Apply updates per vendor instructions.
QNAP Helpdesk contains an improper access control vulnerability which could allow an attacker to gain privileges or to read sensitive information.
What the flaw is
The vulnerability have been reported to affect earlier versions of QTS. If exploited, this improper access control vulnerability could allow attackers to compromise the security of the software by gaining privileges, or reading sensitive information. This issue affects: QNAP Systems Inc. Helpdesk versions prior to 3.0.3.
From the NVD.
Fixes and advisories
Learn this
Explore this week’s weaknesses and all learning topics
Understand the kind of weakness behind this flaw. These resources teach the weakness, rather than reproduce this specific CVE. Follow the vendor's advice above to fix the affected product.
CWE-284 · CISA KEV; NVD record: security@qnapsecurity.com.tw. We have not selected a close learning match for this label.
CWE is a catalogue of weakness types. Labels come from the sources shown and can differ or change. Resource matches reviewed 16 October 2026.
On SentryFeed
No story in the last 14 days has mentioned it.
Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.