Apache flaws being used in attacks
CISA lists 41 flaws in Apache products as being used in attacks, most recently on 8 Oct 2026. 8 have been used in ransomware.
ApacheBeing used in attacks
- On CISA’s list
- 41 flaws, added between 3 Nov 2021 and 8 Oct 2026
- Most recent
- CVE-2016-3081, Apache Struts Command Injection Vulnerability, added 8 Oct 2026
- Used in ransomware
- 8 flaws, according to CISA
- Products
- Struts (6), Tomcat (6), HTTP Server (4), ActiveMQ (3), OFBiz (3), and 16 more
What to do
- Update every Apache product you use.Install the updates Apache offers, on every device, and restart when asked. Each flaw below has a fix or clear advice; that’s one of CISA’s conditions for listing it.
- If someone looks after IT for you, send them this page.Many of these are in equipment you don’t see: routers, firewalls, servers, the office network. Ask them to confirm each one is fixed, or that you don’t use the product.
- Check anything else in the lookup.Search any app, company or CVE. Not being on CISA’s list doesn’t mean safe: keep updating either way.
Every flaw, newest first
- Apache Struts
CVE-2016-3081Apache Struts Command Injection VulnerabilityApache Struts contains a command injection vulnerability that could allow remote attackers to execute arbitrary code via method:prefix when Dynamic Method Invocation is enabled.CISA’s required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Read all
Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. - Apache Tomcat
CVE-2026-34486Apache Tomcat Missing Encryption of Sensitive Data VulnerabilityApache Tomcat contains a missing encryption of sensitive data vulnerability that allows the bypass of the EncryptInterceptor. This vulnerability can be chained with CVE‑2025‑24813.CISA’s required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Read all
Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. - Apache ActiveMQ
CVE-2026-34197Apache ActiveMQ Improper Input Validation VulnerabilityApache ActiveMQ contains an improper input validation vulnerability that allows for code injection.CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. - Apache HTTP Server
CVE-2024-38475Apache HTTP Server Improper Escaping of Output VulnerabilityApache HTTP Server contains an improper escaping of output vulnerability in mod_rewrite that allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure.CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. - Apache Tomcat
CVE-2025-24813Apache Tomcat Path Equivalence VulnerabilityApache Tomcat contains a path equivalence vulnerability that allows a remote attacker to execute code, disclose information, or inject malicious content via a partial PUT request. This vulnerability can be chained with CVE‑2026‑34486.CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. - Apache OFBiz
CVE-2024-45195Apache OFBiz Forced Browsing VulnerabilityApache OFBiz contains a forced browsing vulnerability that allows a remote attacker to obtain unauthorized access.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache HugeGraph-Server
CVE-2024-27348Apache HugeGraph-Server Improper Access Control VulnerabilityApache HugeGraph-Server contains an improper access control vulnerability that could allow a remote attacker to execute arbitrary code.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache OFBiz
CVE-2024-38856Apache OFBiz Incorrect Authorization VulnerabilityApache OFBiz contains an incorrect authorization vulnerability that could allow remote code execution via a Groovy payload in the context of the OFBiz user process by an unauthenticated attacker.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache OFBiz
CVE-2024-32113Apache OFBiz Path Traversal VulnerabilityApache OFBiz contains a path traversal vulnerability that could allow for remote code execution.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache Flink
CVE-2020-17519Apache Flink Improper Access Control VulnerabilityApache Flink contains an improper access control vulnerability that allows an attacker to read any file on the local filesystem of the JobManager through its REST interface.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache Superset
CVE-2023-27524Apache Superset Insecure Default Initialization of Resource VulnerabilityApache Superset contains an insecure default initialization of a resource vulnerability that allows an attacker to authenticate and access unauthorized resources on installations that have not altered the default configured SECRET_KEY according to installation instructions.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache ActiveMQ
CVE-2023-46604Apache ActiveMQ Deserialization of Untrusted Data VulnerabilityApache ActiveMQ contains a deserialization of untrusted data vulnerability that may allow a remote attacker with network access to a broker to run shell commands by manipulating serialized class types in the OpenWire protocol to cause the broker to instantiate any class on the classpath.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache RocketMQ
CVE-2023-33246Apache RocketMQ Command Execution VulnerabilitySeveral components of Apache RocketMQ, including NameServer, Broker, and Controller, are exposed to the extranet and lack permission verification. An attacker can exploit this vulnerability by using the update configuration function to execute commands as the system users that RocketMQ is running as or achieve the same effect by forging the RocketMQ protocol content.CISA’s required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. - Apache Tomcat
CVE-2016-8735Apache Tomcat Remote Code Execution VulnerabilityApache Tomcat contains an unspecified vulnerability that allows for remote code execution if JmxRemoteLifecycleListener is used and an attacker can reach Java Management Extension (JMX) ports. This CVE exists because this listener wasn't updated for consistency with the Oracle patched issues for CVE-2016-3427 which affected credential types.CISA’s required actionApply updates per vendor instructions. - Apache Log4j2
CVE-2021-45046Apache Log4j2 Deserialization of Untrusted Data VulnerabilityApache Log4j2 contains a deserialization of untrusted data vulnerability due to the incomplete fix of CVE-2021-44228, where the Thread Context Lookup Pattern is vulnerable to remote code execution in certain non-default configurations.CISA’s required actionApply updates per vendor instructions. - Apache Spark
CVE-2022-33891Apache Spark Command Injection VulnerabilityApache Spark contains a command injection vulnerability via Spark User Interface (UI) when Access Control Lists (ACLs) are enabled.CISA’s required actionApply updates per vendor instructions. - Apache CouchDB
CVE-2022-24706Apache CouchDB Insecure Default Initialization of Resource VulnerabilityApache CouchDB contains an insecure default initialization of resource vulnerability which can allow an attacker to escalate to administrative privileges.CISA’s required actionApply updates per vendor instructions. - Apache APISIX
CVE-2022-24112Apache APISIX Authentication Bypass VulnerabilityApache APISIX contains an authentication bypass vulnerability that allows for remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache Kylin
CVE-2020-1956Apache Kylin OS Command Injection VulnerabilityApache Kylin contains an OS command injection vulnerability which could permit an attacker to perform remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache Tomcat
CVE-2017-12617Apache Tomcat Remote Code Execution VulnerabilityWhen running Apache Tomcat, it is possible to upload a JSP file to the server via a specially crafted request. This JSP could then be requested and any code it contained would be executed by the server.CISA’s required actionApply updates per vendor instructions. - Apache Tomcat
CVE-2017-12615Apache Tomcat on Windows Remote Code Execution VulnerabilityWhen running Apache Tomcat on Windows with HTTP PUTs enabled, it is possible to upload a JSP file to the server via a specially crafted request. This JSP could then be requested and any code it contained would be executed by the server.CISA’s required actionApply updates per vendor instructions. - Apache Struts
CVE-2013-2251Apache Struts Improper Input Validation VulnerabilityApache Struts allows remote attackers to execute arbitrary Object-Graph Navigation Language (OGNL) expressions.CISA’s required actionApply updates per vendor instructions. - Apache Tomcat
CVE-2020-1938Apache Tomcat Improper Privilege Management VulnerabilityApache Tomcat treats Apache JServ Protocol (AJP) connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited.CISA’s required actionApply updates per vendor instructions. - Apache Struts 1
CVE-2017-9791Apache Struts 1 Improper Input Validation VulnerabilityThe Struts 1 plugin in Apache Struts might allow remote code execution via a malicious field value passed in a raw message to the ActionMessage.CISA’s required actionApply updates per vendor instructions. - Apache ActiveMQ
CVE-2016-3088Apache ActiveMQ Improper Input Validation VulnerabilityThe Fileserver web application in Apache ActiveMQ allows remote attackers to upload and execute arbitrary files via an HTTP PUT followed by an HTTP MOVE requestCISA’s required actionApply updates per vendor instructions. - Apache Struts 2
CVE-2012-0391Apache Struts 2 Improper Input Validation VulnerabilityThe ExceptionDelegator component in Apache Struts 2 before 2.2.3.1 contains an improper input validation vulnerability that allows for remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache Struts 1
CVE-2006-1547Apache Struts 1 ActionForm Denial-of-Service VulnerabilityActionForm in Apache Struts versions before 1.2.9 with BeanUtils 1.7 contains a vulnerability that allows for denial-of-service (DoS).CISA’s required actionApply updates per vendor instructions. - Apache Airflow's Experimental API
CVE-2020-13927Apache Airflow's Experimental API Authentication BypassThe previous default setting for Airflow's Experimental API was to allow all API requests without authentication.CISA’s required actionApply updates per vendor instructions. - Apache Airflow
CVE-2020-11978Apache Airflow Command InjectionA remote code/command injection vulnerability was discovered in one of the example DAGs shipped with Airflow.CISA’s required actionApply updates per vendor instructions. - Apache Log4j2
CVE-2021-44228Apache Log4j2 Remote Code Execution VulnerabilityApache Log4j2 contains a vulnerability where JNDI features do not protect against attacker-controlled JNDI-related endpoints, allowing for remote code execution.CISA’s required actionFor all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; Read all
OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available. - Apache Solr
CVE-2019-0193Apache Solr DataImportHandler Code Injection VulnerabilityThe optional Apache Solr module DataImportHandler contains a code injection vulnerability.CISA’s required actionApply updates per vendor instructions. - Apache
CVE-2021-40438Apache HTTP Server-Side Request Forgery (SSRF)A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.CISA’s required actionApply updates per vendor instructions. - Apache HTTP Server
CVE-2021-42013Apache HTTP Server Path Traversal VulnerabilityApache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default require all denied or if CGI scripts are enabled. This CVE ID resolves an incomplete patch for CVE-2021-41773.CISA’s required actionApply updates per vendor instructions. - Apache HTTP Server
CVE-2021-41773Apache HTTP Server Path Traversal VulnerabilityApache HTTP Server contains a path traversal vulnerability that allows an attacker to perform remote code execution if files outside directories configured by Alias-like directives are not under default �require all denied� or if CGI scripts are enabled. The original patch issued under this CVE ID is insufficient, please review remediation information under CVE-2021-42013.CISA’s required actionApply updates per vendor instructions. - Apache Struts
CVE-2020-17530Apache Struts Remote Code Execution VulnerabilityForced Object-Graph Navigation Language (OGNL) evaluation in Apache Struts, when evaluated on raw user input in tag attributes, can lead to remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache Solr
CVE-2019-17558Apache Solr VelocityResponseWriter Plug-In Remote Code Execution VulnerabilityThe Apache Solr VelocityResponseWriter plug-in contains an unspecified vulnerability which can allow for remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache HTTP Server
CVE-2019-0211Apache HTTP Server Privilege Escalation VulnerabilityApache HTTP Server, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute code with the privileges of the parent process (usually root) by manipulating the scoreboard.CISA’s required actionApply updates per vendor instructions. - Apache Struts
CVE-2018-11776Apache Struts Remote Code Execution VulnerabilityApache Struts contains a vulnerability that allows for remote code execution under two circumstances. One, where the alwaysSelectFullNamespace option is true and the value isn't set for a result defined in underlying configurations and in same time, its upper package configuration have no or wildcard namespace. Or, using URL tag which doesn't have value and action set and in same time, its upper package configuration have no or wildcard namespace.CISA’s required actionApply updates per vendor instructions. - Apache Struts
CVE-2017-9805Apache Struts Deserialization of Untrusted Data VulnerabilityApache Struts REST Plugin uses an XStreamHandler with an instance of XStream for deserialization without any type filtering, which can lead to remote code execution when deserializing XML payloads.CISA’s required actionApply updates per vendor instructions. - Apache Struts
CVE-2017-5638Apache Struts Remote Code Execution VulnerabilityApache Struts Jakarta Multipart parser allows for malicious file upload using the Content-Type value, leading to remote code execution.CISA’s required actionApply updates per vendor instructions. - Apache Shiro
CVE-2016-4437Apache Shiro Code Execution VulnerabilityApache Shiro contains a vulnerability which may allow remote attackers to execute code or bypass intended access restrictions via an unspecified request parameter when a cipher key has not been configured for the "remember me" feature.CISA’s required actionApply updates per vendor instructions.
From CISA’s Known Exploited Vulnerabilities catalog, updated 21 Oct 2026 (version 2026.10.21). CISA’s required actions are written for US government agencies. Apache on CISA’s site.