CASCACascade Atlas

Evidence dossier

CVE-2018-19953

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

Exploited in the wild (CISA KEV since May 24, 2022). NVD reports CVSS 3.1 6.1. EPSS estimates 30.5% exploit likelihood as of Oct 22, 2026.

66.3–77.3Priority evidence range
Evidence through Oct 22, 2026, 6:07 PM UTC

As of Oct 22, 2026

Normalized restatement

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.

State
PUBLISHED
Published
Oct 28, 2020
Updated
Oct 1, 2026
Evidence coverage
85%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: QNAP NAS File Station Cross-Site Scripting Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    QNAP NAS File Station Cross-Site Scripting Vulnerability
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  4. Source dateSource date omittedFirst observed by CASCA
    qnap

    Record text: 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.

    Inspect raw assertion
    Field
    container
    Value
    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.
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 30.53% probability · 98.24th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.305270000000; percentile 0.982400000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date May 24, 2022 · first observed Sep 1, 2026

Exploit likelihood30.53%

FIRST EPSS · score date Oct 22, 2026 · 98.2th percentile · first observed Oct 22, 2026

SeverityCVSS 6.1

NVD · CVSS 3.1 · first observed Oct 2, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusLast verified source snapshot retained

The last verified source boundary remains in force for this claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
Review source contract
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Oct 22, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Oct 22, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA KEVOriginal assertion
Exploitation cataloged

QNAP NAS File Station Cross-Site Scripting Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
QNAP NAS File Station Cross-Site Scripting Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
qnapOriginal assertion
Record text

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.

Inspect raw assertion
Field
container
Value
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.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

30.53% probability · 98.24th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.305270000000; percentile 0.982400000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
12Underlying assertions
1Canonical products
12Target assertions
0Constraint assertions

Grouped from 1 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

6 scope groups

qnap · source assertedQNAP Systems Inc.QTSDirect source scope
Affected: unspecified to before 4.4.2.1231 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "4.4.2.1231", "versionType": "custom"}]
qnap · source assertedQNAP Systems Inc.QTSDirect source scope
Affected: unspecified to before 4.4.1.1201 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "4.4.1.1201", "versionType": "custom"}]
qnap · source assertedQNAP Systems Inc.QTSDirect source scope
Affected: unspecified to before 4.3.6.1218 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "4.3.6.1218", "versionType": "custom"}]
qnap · source assertedQNAP Systems Inc.QTSDirect source scope
Affected: unspecified to before 4.3.4.1190 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "4.3.4.1190", "versionType": "custom"}]
qnap · source assertedQNAP Systems Inc.QTSDirect source scope
Affected: unspecified to before 4.3.3.1161 (custom comparison)Affected: unspecified to before 4.2.6 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "4.3.3.1161", "versionType": "custom"}, {"status": "affected", "version": "unspecified", "lessThan": "4.2.6", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMqnapqtsVulnerable target · 12 assertions
Any version (unconstrained) (< 4.2.6); Any version (unconstrained) (>= 4.3.1.0013, < 4.3.3.1161); Any version (unconstrained) (>= 4.3.4, < 4.3.4.1190); Any version (unconstrained) (>= 4.3.6, < 4.3.6.1218); Any version (unconstrained) (>= 4.4.0, < 4.4.1.1201); Any version (unconstrained) (>= 4.4.2, < 4.4.2.1231); Version 4.2.6Canonical identity product-81578b5d517b13c57b34c6184dee501c7b2e69f5d366148b8e0d95265e548fc9Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:qnap:qts:4.2.6:build_20191107:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 11
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    f6259c86-ffda-40e8-af0c-33cc8c108dc9
  2. cpe:2.3:o:qnap:qts:4.2.6:build_20170517:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 7
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    8f523e9f-d101-4c29-a624-74e1f3f8cb7d
  3. cpe:2.3:o:qnap:qts:4.2.6:-:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 6
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    2d3b1e3a-c9e9-4bb8-8bfc-ae1258722f85
  4. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 4.3.1.0013; through excluding 4.3.3.1161
    Match ID
    dcf2e9d3-12c2-4a5a-bc1d-f2c007303805
  5. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    from including 4.3.4; through excluding 4.3.4.1190
    Match ID
    26b1c1d9-d91e-4c02-87a2-1ede2ab4b0bf
  6. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    from including 4.3.6; through excluding 4.3.6.1218
    Match ID
    4a213877-d365-46db-bda1-4daa020af84a
  7. cpe:2.3:o:qnap:qts:4.2.6:build_20190730:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 9
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    cf3c4461-c1b6-43a1-ba5e-d6658efd06ee
  8. cpe:2.3:o:qnap:qts:4.2.6:build_20190921:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 10
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a1f11848-6fed-4d58-a177-36d280c0347c
  9. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    from including 4.4.2; through excluding 4.4.2.1231
    Match ID
    5bf6e081-b28b-4a26-ba59-eb7a66099360
  10. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    from including 4.4.0; through excluding 4.4.1.1201
    Match ID
    f902afed-e51b-42f2-85bd-db0b19b8c7db
  11. cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 4.2.6
    Match ID
    3777f6cc-9189-4bc0-b336-62ba1efb91a7
  12. cpe:2.3:o:qnap:qts:4.2.6:build_20190322:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 8
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    1388dbe0-f6bb-44ab-81ac-bfb4e70be820

Affected-product evidence

Accepted scope and product mapping

0 canonical links · 2 source-reported links

Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
5
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
1aea784d-cf24-4db4-ac60-5170d8c36fa29e8145d2-517e-431e-bc28-64f2dbf6ff7fa5f0a621-510e-452c-bc5c-25d8c0b0db64c8560846-ad6a-4798-91ba-cf2c76859732ce821f6b-d281-495f-9dbe-c86b4093e5eb
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Nvd cpe vulnerable target
Assertions
12
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
395e1d3d-0099-4ab2-8f37-034c970115f25b6d80dd-7d74-4afc-8cfe-b6bd9d845c855d3128b8-473f-4930-99f3-74d16c525feb7daff5ae-b2c5-443a-b141-e381bcf7653c901e5e7e-d2dd-456b-b6e9-69cc50d5d44d9a91f570-6f7f-4f15-9108-c0f3884db76b9f8afcf6-5ae2-45d5-84f0-b110533b07c5aea03890-5128-43c3-af88-fc14f1fbe382bb22def0-e1ab-4dad-98c8-348bc180091bbc818b18-1935-467f-8c59-7a1f38e0ec69dc2f90a5-83a6-4f7d-b725-ac39524fdd2befb0d5e6-5b7b-43f8-b8d9-7cd04f9eb77f

Assessments

CVSS by origin

6.1
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Direct CVE/CNA normalized decisions

6.1Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Validation
Valid match
Recomputed
6.1
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.