CVE-2021-28169
MEDIUMEPSS 100th pctlDescription
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.
How to fix
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
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Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Exploit Intelligence
Very high risk: more likely to be exploited than 100% of all known CVEs.
References
Related Vulnerabilities
Other CWE-200 (Information Exposure) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-24919 | High | 8.6 | 100% | KEV + Ransom | - |
| CVE-2020-14181 | Medium | 5.3 | 100% | - | Fix |
| CVE-2021-34429 | Medium | 5.3 | 99% | - | Fix |
| CVE-2018-11409 | Medium | 5.3 | 98% | - | - |
| CVE-2021-41277 | Critical | 10.0 | 97% | KEV | - |
| CVE-2016-2183 | High | 7.5 | 96% | - | Fix |
Common questions
How do I fix CVE-2021-28169?
Published advisories record a fix for 37 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2021-28169 being actively exploited?
Not that we know of. CVE-2021-28169 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 78.5% is the estimated probability that it will be exploited in the next 30 days. That is higher than 100% of all scored CVEs.
How severe is CVE-2021-28169?
CVE-2021-28169 has a CVSS v3 base score of 5.3, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-28169 affect?
Published advisories record a fix for jetty-annotations (Amazon), jetty-ant (Amazon), jetty-client (Amazon), jetty-continuation (Amazon), and 33 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.