High Input validation

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 Jan 21, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: apache

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.7% (30-day exploitation probability)+8
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.73%

ahead of 53% of scored CVEs · Oct 14, 2026

Affects

Apache Software Foundation

Solr

CVSS base

7.1

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Solr).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (input validation), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Apache Software Foundation	Solr	≥ 8.6.0 and < 9.10.1	Vulnerable	NIST National Vulnerability Database
Apache Software Foundation	Solr	≥ 8.6 and ≤ 9.10.0	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.1	CVSS 3.1	High	2.8	4.2	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.1	CVSS 3.1	High	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-20 · Improper Input Validation

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.73%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · apache software foundation/apache solr
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 7.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jan 21, 2026 · apache

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

www.openwall.com/lists/oss-security/2026/01/20/5
Mailing List, NIST National Vulnerability Database
lists.apache.org/thread/qkrb9dd4xrlqmmq73lrhkbfkttto2d1m
Mailing List, vendor-advisory, NIST National Vulnerability Database

Elsewhere on this site

Apache Software Foundation
every CVE for this vendor

Input validation
same class

CWE-20
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-44825 Apache Solr: Enabling BasicAuth using bin/solr CLI configures additional insecure users Jun 1, 2026
High CVE-2026-22022 Apache Solr: Unauthorized bypass of certain "predefined permission" rules in the RuleBasedAuthorizationPlugin Jan 21, 2026
High CVE-2023-44487 HTTP/2 Rapid Reset Attack Vulnerability KEV Oct 10, 2023
High CVE-2019-17558 Apache Solr VelocityResponseWriter Plug-In Remote Code Execution Vulnerability KEV Dec 30, 2019
High CVE-2019-0193 Apache Solr DataImportHandler Code Injection Vulnerability KEV Aug 1, 2019

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-22444 is "Apache Solr: Insufficient file-access checking in standalone core-creation requests", rated High. It affects Solr (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.73% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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