SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2024-21899

An improper authentication vulnerability has been reported to affect several QNAP operating system versions.

CRITICAL 9.8EPSS 24.4%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 24.4%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

Description

An improper authentication vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to compromise the security of the system via a network. We have already fixed the vulnerability in the following versions: QTS 5.1.3.2578 build 20231110 and later QTS 4.5.4.2627 build 20231225 and later QuTS hero h5.1.3.2578 build 20231110 and later QuTS hero h4.5.4.2626 build 20231225 and later QuTScloud c5.1.5.2651 and later

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
24.37% probability · 98th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-287
Affected
qnap/qts · qnap/quts hero · qnap/qutscloud
Source
security@qnapsecurity.com.tw
EPSS trend
0%13%25%3 November 2026: 24.37%3 November 20263 November 2026

EPSS 24.4% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.