Apache Software Foundation Apache Solr vulnerabilities
24 vulnerabilities
Known vulnerabilities in Apache Software Foundation Apache Solr, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
CVE-2018-1308apache software foundationapache solr+5
EPSS score20.82%
This vulnerability in Apache Solr 1.2 to 6.6.2 and 7.0.0 to 7.2.1 relates to an XML external entity expansion (XXE) in the `&dataConfig=<inlinexml>` parameter of Solr's DataImportHandler. It 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.CVE-2018-8026apache software foundationapache solr+4EPSS score9.03%
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.CVE-2018-8010apache software foundationapache solr+2EPSS score3.78%
This vulnerability in Apache Solr 6.0.0 to 6.6.3, 7.0.0 to 7.3.0 relates to an XML external entity expansion (XXE) in Solr config files (solrconfig.xml, schema.xml, managed-schema). 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. Users are advised to upgrade to either Solr 6.6.4 or Solr 7.3.1 releases both of which address the vulnerability. Once upgrade is complete, no other steps are required. Those releases only allow external entities and Xincludes that refer to local files / zookeeper resources below the Solr instance directory (using Solr's ResourceLoader); usage of absolute URLs is denied. Keep in mind, that external entities and XInclude are explicitly supported to better structure config files in large installations. Before Solr 6 this was no problem, as config files were not accessible through the APIs.CVE-2021-29943apache software foundationapache solr+3EPSS score4.67%
When using ConfigurableInternodeAuthHadoopPlugin for authentication, Apache Solr versions prior to 8.8.2 would forward/proxy distributed requests using server credentials instead of original client credentials. This would result in incorrect authorization resolution on the receiving hosts.CVE-2021-29262apache software foundationapache solr+3EPSS score6.72%
When starting Apache Solr versions prior to 8.8.2, configured with the SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider and no existing security.json znode, if the optional read-only user is configured then Solr would not treat that node as a sensitive path and would allow it to be readable. Additionally, with any ZkACLProvider, if the security.json is already present, Solr will not automatically update the ACLs.CVE-2021-27905apache software foundationapache solr+4EPSS score93.05%
The ReplicationHandler (normally registered at "/replication" under a Solr core) in Apache Solr has a "masterUrl" (also "leaderUrl" alias) parameter that is used to designate another ReplicationHandler on another Solr core to replicate index data into the local core. To prevent a SSRF vulnerability, Solr ought to check these parameters against a similar configuration it uses for the "shards" parameter. Prior to this bug getting fixed, it did not. This problem affects essentially all Solr versions prior to it getting fixed in 8.8.2.CVE-2021-44548apache software foundationapache solr+2EPSS score5.23%
An Improper Input Validation vulnerability in DataImportHandler of Apache Solr allows an attacker to provide a Windows UNC path resulting in an SMB network call being made from the Solr host to another host on the network. If the attacker has wider access to the network, this may lead to SMB attacks, which may result in: * The exfiltration of sensitive data such as OS user hashes (NTLM/LM hashes), * In case of misconfigured systems, SMB Relay Attacks which can lead to user impersonation on SMB Shares or, in a worse-case scenario, Remote Code Execution This issue affects all Apache Solr versions prior to 8.11.1. This issue only affects Windows.CVE-2025-24814apache software foundationapache solr+11EPSS score1.17%
Core creation allows users to replace "trusted" configset files with arbitrary configuration
Solr instances that (1) use the "FileSystemConfigSetService" component (the default in "standalone" or "user-managed" mode), and (2) are running without authentication and authorization are vulnerable to a sort of privilege escalation wherein individual "trusted" configset files can be ignored in favor of potentially-untrusted replacements available elsewhere on the filesystem. These replacement config files are treated as "trusted" and can use "<lib>" tags to add to Solr's classpath, which an attacker might use to load malicious code as a searchComponent or other plugin.
This issue affects all Apache Solr versions up through Solr 9.7. Users can protect against the vulnerability by enabling authentication and authorization on their Solr clusters or switching to SolrCloud (and away from "FileSystemConfigSetService"). Users are also recommended to upgrade to Solr 9.8.0, which mitigates this issue by disabling use of "<lib>" tags by default.CVE-2017-9803apache software foundationapache solr+2EPSS score2.19%
Apache Solr's Kerberos plugin can be configured to use delegation tokens, which allows an application to reuse the authentication of an end-user or another application. There are two issues with this functionality (when using SecurityAwareZkACLProvider type of ACL provider e.g. SaslZkACLProvider). Firstly, access to the security configuration can be leaked to users other than the solr super user. Secondly, malicious users can exploit this leaked configuration for privilege escalation to further expose/modify private data and/or disrupt operations in the Solr cluster. The vulnerability is fixed from Apache Solr 6.6.1 onwards.CVE-2017-7660apache software foundationapache solr+2EPSS score5.63%
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.CVE-2017-3163apache software foundationapache solr+4EPSS score6.56%
When using the Index Replication feature, Apache Solr nodes can pull index files from a master/leader node using an HTTP API which accepts a file name. However, Solr before 5.5.4 and 6.x before 6.4.1 did not validate the file name, hence it was possible to craft a special request involving path traversal, leaving any file readable to the Solr server process exposed. Solr servers protected and restricted by firewall rules and/or authentication would not be at risk since only trusted clients and users would gain direct HTTP access.CVE-2017-3164apache software foundationapache solr+4EPSS score19.44%
Server Side Request Forgery in Apache Solr, versions 1.3 until 7.6 (inclusive). Since the "shards" parameter does not have a corresponding whitelist mechanism, a remote attacker with access to the server could make Solr perform an HTTP GET request to any reachable URL.CVE-2024-52012apache software foundationapache solr+9EPSS score44.99%
Relative Path Traversal vulnerability in Apache Solr.
Solr instances running on Windows are vulnerable to arbitrary filepath write-access, due to a lack of input-sanitation in the "configset upload" API. Commonly known as a "zipslip", maliciously constructed ZIP files can use relative filepaths to write data to unanticipated parts of the filesystem.
This issue affects Apache Solr: from 6.6 through 9.7.0.
Users are recommended to upgrade to version 9.8.0, which fixes the issue. Users unable to upgrade may also safely prevent the issue by using Solr's "Rule-Based Authentication Plugin" to restrict access to the configset upload API, so that it can only be accessed by a trusted set of administrators/users.CVE-2024-45217apache software foundationapache solr+3EPSS score0.74%
Insecure Default Initialization of Resource vulnerability in Apache Solr.
New ConfigSets that are created via a Restore command, which copy a configSet from the backup and give it a new name, are created without setting the "trusted" metadata.
ConfigSets that do not contain the flag are trusted implicitly if the metadata is missing, therefore this leads to "trusted" ConfigSets that may not have been created with an Authenticated request.
"trusted" ConfigSets are able to load custom code into classloaders, therefore the flag is supposed to only be set when the request that uploads the ConfigSet is Authenticated & Authorized.
This issue affects Apache Solr: from 6.6.0 before 8.11.4, from 9.0.0 before 9.7.0. This issue does not affect Solr instances that are secured via Authentication/Authorization.
Users are primarily recommended to use Authentication and Authorization when running Solr. However, upgrading to version 9.7.0, or 8.11.4 will mitigate this issue otherwise.CVE-2024-45216apache software foundationapache solr+3EPSS score92.75%
Improper Authentication vulnerability in Apache Solr.
Solr instances using the PKIAuthenticationPlugin, which is enabled by default when Solr Authentication is used, are vulnerable to Authentication bypass.
A fake ending at the end of any Solr API URL path, will allow requests to skip Authentication while maintaining the API contract with the original URL Path.
This fake ending looks like an unprotected API path, however it is stripped off internally after authentication but before API routing.
This issue affects Apache Solr: from 5.3.0 before 8.11.4, from 9.0.0 before 9.7.0.
Users are recommended to upgrade to version 9.7.0, or 8.11.4, which fix the issue.CVE-2019-0192apache software foundationapache solr+4EPSS score78.23%
In Apache Solr versions 5.0.0 to 5.5.5 and 6.0.0 to 6.6.5, the Config API allows to configure the JMX server via an HTTP POST request. By pointing it to a malicious RMI server, an attacker could take advantage of Solr's unsafe deserialization to trigger remote code execution on the Solr side.CVE-2026-22444apache software foundationapache solr+9EPSS score0.69%
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.CVE-2026-22022apache software foundationapache solr+9EPSS score0.58%
Deployments of Apache Solr 5.3.0 through 9.10.0 that rely on Solr's "Rule Based Authorization Plugin" are vulnerable to allowing unauthorized access to certain Solr APIs, due to insufficiently strict input validation in those components. Only deployments that meet all of the following criteria are impacted by this vulnerability:
* Use of Solr's "RuleBasedAuthorizationPlugin"
* A RuleBasedAuthorizationPlugin config (see security.json) that specifies multiple "roles"
* A RuleBasedAuthorizationPlugin permission list (see security.json) that uses one or more of the following pre-defined permission rules: "config-read", "config-edit", "schema-read", "metrics-read", or "security-read".
* A RuleBasedAuthorizationPlugin permission list that doesn't define the "all" pre-defined permission
* A networking setup that allows clients to make unfiltered network requests to Solr. (i.e. user-submitted HTTP/HTTPS requests reach Solr as-is, unmodified or restricted by any intervening proxy or gateway)
Users can mitigate this vulnerability by ensuring that their RuleBasedAuthorizationPlugin configuration specifies the "all" pre-defined permission and associates the permission with an "admin" or other privileged role. Users can also upgrade to a Solr version outside of the impacted range, such as the recently released Solr 9.10.1.CVE-2026-44825apache software foundationapache solr+8EPSS score2.84%
Hardcoded credentials in the Basic Authentication setup tool (bin/solr auth enable) in Apache Solr versions 9.4.0 through 9.10.1 and 10.0.0 allows a remote attacker to gain full administrative access to the cluster via publicly known default credentials installed silently alongside the user-specified account.
As an immediate workaround without upgrading, delete the template users (superadmin, admin, search, index) from security.json or change their passwords.
The future, not yet released, versions 9.11.0 and 10.1.0 will not be vulnerable, and it will be enough to upgrade to solve the issue.
Not affected:
* Clusters where bin/solr auth enable was not used to bootstrap BasicAuth
* Clusters where template users have been assigned strong passwords after bootstrapCVE-2023-50292apache software foundationapache solr+4EPSS score3.02%
Incorrect Permission Assignment for Critical Resource, Improper Control of Dynamically-Managed Code Resources vulnerability in Apache Solr.
This issue affects Apache Solr: from 8.10.0 through 8.11.2, from 9.0.0 before 9.3.0.
The Schema Designer was introduced to allow users to more easily configure and test new Schemas and configSets.
However, when the feature was created, the "trust" (authentication) of these configSets was not considered.
External library loading is only available to configSets that are "trusted" (created by authenticated users), thus non-authenticated users are unable to perform Remote Code Execution.
Since the Schema Designer loaded configSets without taking their "trust" into account, configSets that were created by unauthenticated users were allowed to load external libraries when used in the Schema Designer.
Users are recommended to upgrade to version 9.3.0, which fixes the issue.