If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code.

published 2020-10-28 6 y ago modified 2026-10-01 39 d ago also EUVD-2018-11624

cvss: 6.1; version 3.1, CNA
cisa kev: Exploited; added 2022-05-24, used in ransomware
epss: 30.5%; EPSS 30.5% chance of exploitation in 30 days, percentile 98%
public exploits: 0; none known

If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed the issue in the following QTS versions. QTS 4.4.2.1231 on build 20200302; QTS 4.4.1.1201 on build 20200130; QTS 4.3.6.1218 on build 20200214; QTS 4.3.4.1190 on build 20200107; QTS 4.3.3.1161 on build 20200109; QTS 4.2.6 on build 20200109.

Patch / fix

cisa required action Apply updates per vendor instructions.

fixed in 1

QNAP Systems Inc. QTS 4.2.6, 4.3.3.1161, 4.3.4.1190, 4.3.6.1218, 4.4.1.1201, 4.4.2.1231

Timeline

2020-10-28 Published
2022-05-24 Added to CISA KEV
2022-06-14 CISA patch deadline
2026-08-13 CISA SSVC: exploitation active

Known exploited

Added: 4 y ago (2022-05-24)
Patch by: 2022-06-14 (4 y ago)
Ransomware: Known to be used in ransomware campaigns
Required action: Apply updates per vendor instructions.
Vendor, product: QNAP, Network Attached Storage (NAS)
CISA name: QNAP NAS File Station Cross-Site Scripting Vulnerability

CISA SSVC

Exploitation: Active, exploited in the wild
Automatable: no
Technical impact: total
Assessed: 2 mo ago (2026-08-13)

Exploit prediction

30.53% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

QNAP Systems Inc. QTS

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page

References

qnap.com /zh-tw/security-advisory/qsa-20-01
vendor-advisory
cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-19953
government-resource, us-government-resource

Sources

CVE List CVE-2018-19953
NVD CVE-2018-19953

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary