Apache Solr insecure inter-node communication

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2017-7660: 5.63% estimated exploitation activity in the next 30 days; percentile 92.96 (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 uses a PKI based mechanism to secure inter-node communication when security is enabled. It is possible to create a specially crafted node name that does not exist as part of the cluster and point it to a malicious node. This can trick the nodes in cluster to believe that the malicious node is a member of the cluster. So, if Solr users have enabled BasicAuth authentication mechanism using the BasicAuthPlugin or if the user has implemented a custom Authentication plugin, which does not implement either "HttpClientInterceptorPlugin" or "HttpClientBuilderPlugin", his/her servers are vulnerable to this attack. Users who only use SSL without basic authentication or those who use Kerberos are not affected.

Published by the source

14 May 2022, 01:56 UTC

Last modified by the source

29 Jan 2023, 05:03 UTC

Source last checked

26 Oct 2026, 16:02 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-c82r-qg3w-q5mv

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# Patch Next advisory brief: CVE-2017-7660

Advisory: Apache Solr insecure inter-node communication
IDs: CVE-2017-7660, GHSA-c82r-qg3w-q5mv
Record: https://patchnext.com/advisories/cve-2017-7660 (revision 1, source checked 26 Oct 2026, 16:02 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: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.apache.solr:solr-core 6.6.0, 5.5.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.solr:solr-core: affected >= 5.3.0, < 5.5.5; >= 6.0.0, < 6.6.0; fixed in 6.6.0, 5.5.5

## 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?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-c82r-qg3w-q5mv (GitHub-reviewed advisory GHSA-c82r-qg3w-q5mv lists affected ranges: Maven org.apache.solr:solr-core >=5.3.0 =6.0.0 <6.6.0)

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