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Weekly Signal
Live intelligence Updated 19 Aug 2026 · 20:27 UTC

Apache, Oracle · Solr, Primavera Unifier

CVE-2019-17558

Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. Apply updates per vendor instructions.

View response plan
CVSS7.5
EPSS98.6%
KEVYes
ExploitationConfirmed exploitation
RemediationExplicit patch identified ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 98.6%; technical severity is CVSS 7.5.

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).

Who should care

  • Teams operating Solr, Primavera Unifier
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Solr, Primavera Unifier is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Apply updates per vendor instructions.
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Patch

Required Action

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-74
Affected versions
Apache Solr (Start Including 5.0.0, End Excluding 7.7.3 | Start Including 8.0.0, End Excluding 8.4.0); Oracle Primavera Unifier (Start Including 17.7, End Including 17.12 | Version 16.1 | Version 16.2 | Version 18.8)
Fixed versions
Apache Solr (Fixed from 7.7.3, 8.4.0)
Published
30 December 2019
Attack vector
Network
Privileges required
Low
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 98.6%
  4. Signal calculated at 82

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.