What is CVE-2017-9804?

CVE-2017-9804 is a high-severity vulnerability in Apache Struts, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2017-09-20.

How severe is CVE-2017-9804?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2017-9804 known to be exploited?

6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in Apache Struts

CVE-2017-9804

In Apache Struts 2.3.7 through 2.3.33 and 2.5 through 2.5.12, if an application allows entering a URL in a form field and built-in URLValidator is used, it is possible to prepare a special URL which will be used to overload server process when performing validation of the URL. NOTE: this vulnerability exists because of an incomplete fix for S2-047 / CVE-2017-7672.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2017-09-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.082 (94.7th percentile), scored 2026-10-07.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.082 · newest: 0.082 · change: 0.000

Affected products

Apache Struts — versions 2.3.7, 2.3.8, 2.3.9
Apache Software Foundation Struts — versions 2.3.7 - 2.3.33, 2.5 - 2.5.12

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

References

www.oracle.com/technetwork/security-advisory/alert-cve-2017-9805-3889403.html (Patch, Third Party Advisory)
tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170907… (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/100612 (VDB Entry, Third Party Advisory, vdb-entry)
security.netapp.com/advisory/ntap-20180629-0001/
www.arubanetworks.com/assets/alert/ARUBA-PSA-2017-003.txt (Third Party Advisory)
www.securitytracker.com/id/1039261 (VDB Entry, Third Party Advisory, vdb-entry)
struts.apache.org/docs/s2-050.html (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2017-9804?: CVE-2017-9804 is a high-severity vulnerability in Apache Struts, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2017-09-20.
How severe is CVE-2017-9804?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2017-9804 known to be exploited?: 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.