Is CVE-2021-28169 actively exploited?

Yes. CVE-2021-28169 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-28169 be exploited remotely?

The attack vector of CVE-2021-28169 has not been classified yet.

What is the CVSS score of CVE-2021-28169?

CVE-2021-28169 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-28169

UNKNOWNCISA KEVIN THE WILD

CVE-2021-28169

Published: April 11, 2026

EPSS:90.26%probability of exploitation in 30 daysPercentile:99.6th

Official Description

For Eclipse Jetty versions <= 9.4.40, <= 10.0.2, <= 11.0.2, it is possible for requests to the ConcatServlet with a doubly encoded path to access protected resources within the WEB-INF directory. For example a request to `/concat?/%2557EB-INF/web.xml` can retrieve the web.xml file. This can reveal sensitive information regarding the implementation of a web application.

NVD Source

Technical Analysis

CVE-2021-28169 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-28169 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.