How severe is CVE-2019-17558?

CVE-2019-17558 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2019-17558?

CVE-2019-17558 affects the following packages: org.apache.solr:solr-core (Maven), org.apache.solr:solr-core (Maven), org.apache.solr:solr-core (Maven), org.apache.solr:solr-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2019-17558?

Update org.apache.solr:solr-core to 8.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-17558 is resolved across your whole dependency graph.

How do I detect CVE-2019-17558 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.solr:solr-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2019-17558 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2019-17558?

O3 pinpoints whether CVE-2019-17558 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2019-17558 actively exploited in the wild?

Yes. There are 12 known exploit references for CVE-2019-17558, including 2 documented proof-of-concept exploits on Exploit-DB and 9 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2019-17558?

CVE-2019-17558 has an EPSS (Exploit Prediction Scoring System) score of 98.6%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2019-17558 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2019-17558 (Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2019-17558?

CVE-2019-17558 is classified as CWE-74 (CWE-74). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2019-17558?

A Nuclei detection template exists for CVE-2019-17558, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2019-17558 published, and has it been updated?

CVE-2019-17558 was published on December 30, 2019 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2021-11-03 — agencies required to remediate by 2022-05-03

☕ Maven

CVE-2019-17558

HIGH

Improper Input Validation in Apache Solr

Also known asGHSA-ww97-9w65-2crx

Published

Dec 30, 2019

Updated

Jul 8, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

12 known

EPSS Exploitation Probability

via FIRST.org ↗

98.6%probability of exploitation in next 30 days

Very High Risk100th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

4 pkgs affected

☕org.apache.solr:solr-core☕org.apache.solr:solr-core☕org.apache.solr:solr-core☕org.apache.solr:solr-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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).

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.solr:solr-core`	≥ 5.0.0&&< 8.4.0	8.4.0
☕Maven	`org.apache.solr:solr-core`	≥ 6.0.0&&< 8.4.0	8.4.0
☕Maven	`org.apache.solr:solr-core`	≥ 7.0.0&&< 8.4.0	8.4.0
☕Maven	`org.apache.solr:solr-core`	≥ 8.0.0&&< 8.4.0	8.4.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-48338remotemultiple✓ Verified

Apache Solr - Remote Code Execution via Velocity Template (Metasploit)

by Metasploit · Apr 16, 2020

Exploit-DB Source

EDB-47572webappsjava

Apache Solr 8.2.0 - Remote Code Execution

by @l3x_wong · Nov 1, 2019

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.solr:solr-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.solr:solr-core to 8.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-17558 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2019-17558 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2019-17558. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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

O3 Security · Impact-Aware SCA

Is CVE-2019-17558 in your dependencies?

O3 detects CVE-2019-17558 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works