Improper Input Validation in Apache Solr

Exploitation

Confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.

CVSS

7.5 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:H

EPSS

• CVE-2019-17558: 98.57% estimated exploitation activity in the next 30 days; percentile 99.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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).

Published by the source

12 Feb 2020, 18:45 UTC

Last modified by the source

22 Oct 2025, 17:45 UTC

Source last checked

26 Oct 2026, 16:40 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-ww97-9w65-2crx

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# Patch Next advisory brief: CVE-2019-17558

Advisory: Improper Input Validation in Apache Solr
IDs: CVE-2019-17558, GHSA-ww97-9w65-2crx
Record: https://patchnext.com/advisories/cve-2019-17558 (revision 1, source checked 26 Oct 2026, 16:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.
Vendor response: Vendor fix available; fixed versions by package: org.apache.solr:solr-core 8.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.solr:solr-core: affected >= 5.0.0, <= 5.5.5; >= 6.0.0, <= 6.6.6; >= 7.0.0, <= 7.7.2; >= 8.0.0, <= 8.3.1; fixed in 8.4.0

## Suggested inspection (read-only)
- Maven org.apache.solr:solr-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.apache.solr:solr-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CISA added CVE-2019-17558 to the Known Exploited Vulnerabilities catalog on 2021-11-03.)
- Verified: https://github.com/advisories/GHSA-ww97-9w65-2crx (GitHub-reviewed advisory GHSA-ww97-9w65-2crx lists affected ranges: Maven org.apache.solr:solr-core >=5.0.0 =6.0.0 =7.0.0 =8.0.0 <=8.3.1)

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