Exploited vulnerability · CISA KEV

Is CVE-2016-8735 exploited? Yes: in CISA KEV since 12 May 2023

Gociux · Apache Tomcat · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2016-8735, Apache Tomcat Remote Code Execution Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 12 May 2023, 2227 days after it was published. It affects Apache Tomcat. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 12 May 2023

ransomwareNot knownno confirmed use

EPSStop 1%among the most likely CVEs to be exploited

severity9.8CVSS 3.1 · critical

US federal due2 Jun 2023BOD 22-01 deadline

What it is

Apache 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.

Vendor	Apache (41 exploited CVEs in KEV)
Product	Tomcat
Vulnerability	Apache Tomcat Remote Code Execution Vulnerability
Weakness	CWE-284
Published	6 Apr 2017
Added to KEV	12 May 2023
Reported by (CNA)	apache

What to do

Check whether you run it. Look for Tomcat in your asset inventory, including appliances and cloud images. Stack check lists every exploited Apache CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 6 Apr 2017.
Get told next time. Email alerts when CISA adds a CVE for Apache.

Other exploited CVEs in Tomcat

CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability (4 Aug 2026)
CVE-2025-24813: Apache Tomcat Path Equivalence Vulnerability (1 Apr 2025)
CVE-2017-12617: Apache Tomcat Remote Code Execution Vulnerability (25 Mar 2022)
CVE-2017-12615: Apache Tomcat on Windows Remote Code Execution Vulnerability (25 Mar 2022)
CVE-2020-1938: Apache Tomcat Improper Privilege Management Vulnerability (3 Mar 2022)

References

Questions

Is CVE-2016-8735 being exploited?

Yes. CISA added CVE-2016-8735 to the Known Exploited Vulnerabilities catalog on 12 May 2023, which means there is reliable evidence of exploitation in the wild.

Is CVE-2016-8735 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2016-8735?

Apply updates per vendor instructions. Check Apache's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Tomcat and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2023 · Apache scorecard · act-now radar.

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