CVE-2026-22444 | Apache Solr: Insufficient file-access checking in standalone core-creation requests

The "create core" API of Apache Solr 8.6 through 9.10.0 lacks sufficient input validation on some API parameters, which can cause Solr to check the existence of and attempt to read file-system paths that should be disallowed by Solr's "allowPaths" security setting https://https://solr.apache.org/guide/solr/latest/configuration-guide/configuring-solr-xml.html#the-solr-element .  These read-only accesses can allow users to create cores using unexpected configsets if any are accessible via the filesystem.  On Windows systems configured to allow UNC paths this can additionally cause disclosure of NTLM "user" hashes.  Solr deployments are subject to this vulnerability if they meet the following criteria: * Solr is running in its "standalone" mode. * Solr's "allowPath" setting is being used to restrict file access to certain directories. * Solr's "create core" API is exposed and accessible to untrusted users.  This can happen if Solr's RuleBasedAuthorizationPlugin https://solr.apache.org/guide/solr/latest/deployment-guide/rule-based-authorization-plugin.html is disabled, or if it is enabled but the "core-admin-edit" predefined permission (or an equivalent custom permission) is given to low-trust (i.e. non-admin) user roles. Users can mitigate this by enabling Solr's RuleBasedAuthorizationPlugin (if disabled) and configuring a permission-list that prevents untrusted users from creating new Solr cores.  Users should also upgrade to Apache Solr 9.10.1 or greater, which contain fixes for this issue.

Published: 2026-01-21 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-22444 is rated Moderate Risk (45.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.65%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-22444

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.65% +0.63%
2 2026-02-18 0.05% 0.03% -0.02%
3 2026-01-27 0.05%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-22444

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 4.2 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-22444

GitHub Security Advisory for CVE-2026-22444

GHSA-vc2w-4v3p-2mqw · Severity: high · Ecosystem: maven — Apache Solr: Insufficient file-access checking in standalone core-creation requests

OS Trackers for CVE-2026-22444

vendor priority summary link
debian unimportant CVE-2026-22444 unimportant priority: Debian including 1 source packages (lucene-solr), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-22444
redhat medium https://access.redhat.com/security/cve/CVE-2026-22444
ubuntu medium CVE-2026-22444 medium priority: Ubuntu including 1 source packages (lucene-solr), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 7, not-affected 1. https://ubuntu.com/security/CVE-2026-22444

Affected software / configurations for CVE-2026-22444

Vendor Product Version Raw CPE
apache solr >= 8.6.0, < 9.10.1 cpe:2.3:a:apache:solr:*:*:*:*:*:*:*:*

References for CVE-2026-22444

cvelogic Threat Intelligence