CASCACascade Atlas

Evidence dossier

CVE-2019-17558

Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter.

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 7.5. EPSS estimates 98.6% exploit likelihood as of Aug 8, 2026.

82.8–83.9Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).

State
PUBLISHED
Published
Dec 30, 2019
Updated
Oct 21, 2025
Evidence coverage
98%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    apache

    Record text: Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).

    Inspect raw assertion
    Field
    container
    Value
    Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).
    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 dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 98.57% probability · 99.92th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.985670000000; percentile 0.999170000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026

Exploit likelihood98.57%

FIRST EPSS · score date Aug 8, 2026 · 99.9th percentile · first observed Aug 8, 2026

SeverityCVSS 7.5

NVD · CVSS 3.1 · first observed Jul 19, 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 statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 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
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

apacheOriginal assertion
Record text

Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).

Inspect raw assertion
Field
container
Value
Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configset could contain renderable, potentially malicious, templates. Parameter provided templates are disabled by default, but can be enabled by setting `params.resource.loader.enabled` by defining a response writer with that setting set to `true`. Defining a response writer requires configuration API access. Solr 8.4 removed the params resource loader entirely, and only enables the configset-provided template rendering when the configset is `trusted` (has been uploaded by an authenticated user).
Source dateSource date omittedFirst 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 ↗
CISA KEVOriginal assertion
Exploitation cataloged

Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

98.57% probability · 99.92th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.985670000000; percentile 0.999170000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
7Underlying assertions
2Canonical products
7Target assertions
0Constraint assertions

Grouped from 2 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

3 scope groups

apache · source assertedn/aApache SolrDirect source scope
Affected: Apache Solr 5.0.0 to Apache Solr 8.3.1
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "Apache Solr 5.0.0 to Apache Solr 8.3.1"}]
NVD CPE · APPLICATIONapachesolrVulnerable target · 2 assertions
Any version (unconstrained) (>= 5.0.0, < 7.7.3); Any version (unconstrained) (>= 8.0.0, < 8.4.0)Canonical identity product-b2893c436d20eeea3899b65735644a7c662137429e9b2fba8a3cdbf6d307d1afLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:apache:solr:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 8.0.0; through excluding 8.4.0
    Match ID
    4ae21606-4430-4ce0-acfe-860199dc6d96
  2. cpe:2.3:a:apache:solr:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    from including 5.0.0; through excluding 7.7.3
    Match ID
    fb21c976-bdb8-4c23-8d75-d80eed433743
NVD CPE · APPLICATIONoracleprimavera_unifierVulnerable target · 5 assertions
Any version (unconstrained) (>= 17.7, <= 17.12); Version 16.1; Version 16.2; Version 18.8; Version 19.12Canonical identity product-631d8e7004a6d0f70fea5b89392ce7a90aa4a82ce15563baac3a7a02ccee0684Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:oracle:primavera_unifier:19.12:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    10864586-270e-4acf-bdcc-ecfcd299305f
  2. cpe:2.3:a:oracle:primavera_unifier:18.8:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    202ad518-2e9b-4062-b063-9858ae1f9ce2
  3. cpe:2.3:a:oracle:primavera_unifier:16.1:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    d55a54fd-7dd1-49cd-be81-0be73990943c
  4. cpe:2.3:a:oracle:primavera_unifier:16.2:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    82eb08c0-2d46-4635-88df-e54f6452d3a3
  5. cpe:2.3:a:oracle:primavera_unifier:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    from including 17.7; through including 17.12
    Match ID
    08fa59a8-6a62-4b33-8952-d6e658f8dac9

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-b1377626da187dbea1eeb98f365c57a3dcbeccfdc2a7d3471e94ece7b6f88e55 · product-631d8e7004a6d0f70fea5b89392ce7a90aa4a82ce15563baac3a7a02ccee0684

Source class
Nvd cpe vulnerable target
Assertions
5
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
35639d54-cfca-45d3-9a94-be0254dd87c839bb8f3b-8d09-40fa-a99c-21ec01ceee8944339245-98ff-4f9c-8fcc-d35ab328a0e0bc2afc58-9285-4be6-91e2-8a914f9f9cadfb8331f9-61a1-49f3-85f2-be80c8d2568a
Mapping establishedEvidence supported

vendor-8771dac0ae5eeec984ca23e4bbe5a243fb7896ad7c1c4afc6acd3abe53fdd152 · product-b2893c436d20eeea3899b65735644a7c662137429e9b2fba8a3cdbf6d307d1af

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
1b6f2237-8301-46b5-81bb-08eb8be7540cf1ed7a22-05cd-40a7-9186-c5e5426ba0d7
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
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
eabe59e3-2c1b-4304-a6e7-5e1b670a15d5

Assessments

CVSS by origin

7.5
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:H/Au:S/C:P/I:P/A:P
7.5
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.5
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

7.5Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
7.5
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.