What is CVE-2018-8026?

CVE-2018-8026 is a medium-severity vulnerability in Apache Solr, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 5.5/10. Published 2018-07-05.

How severe is CVE-2018-8026?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Is CVE-2018-8026 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XXE in Apache Solr

CVE-2018-8026

This vulnerability in Apache Solr 6.0.0 to 6.6.4 and 7.0.0 to 7.3.1 relates to an XML external entity expansion (XXE) in Solr config files (currency.xml, enumsConfig.xml referred from schema.xml, TIKA parsecontext config file). In addition, Xinclude functionality provided in these config files is also affected in a similar way. The vulnerability can be used as XXE using file/ftp/http protocols in order to read arbitrary local files from the Solr server or the internal network. The manipulated files can be uploaded as configsets using Solr's API, allowing to exploit that vulnerability.

Vulnerability class: XXE (XML External Entity)

Published 2018-07-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.090 (95.1th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 95.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.090 · newest: 0.090 · change: 0.000

Affected products

Apache Solr
Apache Software Foundation Solr — versions 6.0.0 to 6.6.4, 7.0.0 to 7.3.1
NetApp Snapcenter
NetApp Storage Automation Store

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

Public proof-of-concept exploits

References

www.securityfocus.com/bid/104690 (VDB Entry, Third Party Advisory, vdb-entry)
issues.apache.org/jira/browse/SOLR-12450 (Exploit, Issue Tracking, Vendor Advisory)
security.netapp.com/advisory/ntap-20190307-0002/ (Third Party Advisory)
mail-archives.apache.org/mod_mbox/lucene-solr-user/201807.mbox/<0cdc01d413b7$f9… (Vendor Advisory, mailing-list, Mailing List)

Frequently asked questions

What is CVE-2018-8026?: CVE-2018-8026 is a medium-severity vulnerability in Apache Solr, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 5.5/10. Published 2018-07-05.
How severe is CVE-2018-8026?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2018-8026 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.