CVE-2018-19953
QNAP NAS (QTS / QuTS hero) · Backup, storage and NAS
QNAP NAS File Station Cross-Site Scripting Vulnerability
At a glance
Exploited. Added to CISA’s catalog of exploited vulnerabilities on May 24, 2022.
Used in ransomware attacks, according to CISA.
Affected product: QNAP NAS (QTS / QuTS hero) (category Backup, storage and NAS, indicative classification). Name in CISA’s catalog: QNAP Network Attached Storage (NAS).
What should I do?
Apply the security update from QNAP.
Deadline set by CISA for US federal agencies: 21 days (due June 14, 2022). It only binds those agencies, but it is a useful measure of urgency.
- QNAP security advisories page (general page, not the advisory for this vulnerability)
- The vendor’s specific advisory is listed in the NVD references: CVE-2018-19953 on the NVD website.
Original text of the required action (CISA)
Apply updates per vendor instructions.
Timeline
- Vulnerability published Publication date (NVD)
- Exploitation confirmed Added to CISA’s KEV catalog
- CISA deadline Remediation deadline set for US federal agencies
The facts, with their sources
- Exploitation confirmed
- Yes, on May 24, 2022 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Ransomware
- Known use Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Hunt for compromise
- Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA required action
- Apply the security update from QNAP. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CISA deadline
- June 14, 2022, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- Vulnerability published
- October 28, 2020 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
- Product according to CISA
- QNAP Network Attached Storage (NAS) Filed by this site under “Backup, storage and NAS” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Severity and activity
FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.
Description
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.
Official description from the NVD, collected Sep 29, 2026. CVE® description © The MITRE Corporation.
A cross-site scripting vulnerability affecting QNAP NAS File Station could allow remote attackers to inject malicious code.
Summary from CISA (KEV catalog).
CERT-FR advisories
No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.
Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.
Sources for this page
- CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
- NVD (NIST): CVSS severity, publication date, description, vendor references.
- EPSS (FIRST): probability of exploitation.
- CERT-FR: advisories and alerts (in French).
- Brand and category: indicative classification by this site (method).