CVE-2016-8738

In Apache Struts 2.5 through 2.5.5, if an application allows entering a URL in a form field and the 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.

Published: 2017-09-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-8738 is rated Moderate Risk (56.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.35%). EPSS rose +2.24% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-8738

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.11% 3.35% +2.24%
2 2026-03-04 0.60% 1.11% +0.51%
3 2025-06-22 — 0.60% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-8738

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.0 MEDIUM
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2016-8738

GitHub Security Advisory for CVE-2016-8738

GHSA-86vq-8qhc-5rqw · Severity: medium · Ecosystem: maven — Apache Struts vulnerable to possible DoS attack when using URLValidator

OS Trackers for CVE-2016-8738

vendor priority summary link
ubuntu medium CVE-2016-8738 medium priority: Ubuntu including 1 source packages (libstruts1.2-java), 7 status rows across 7 suites (artful, bionic, cosmic, trusty, upstream, xenial, zesty): DNE 6, needs-triage 1. https://ubuntu.com/security/CVE-2016-8738

Affected software / configurations for CVE-2016-8738

Vendor Product Version Raw CPE
apache struts 2.5 cpe:2.3:a:apache:struts:2.5:*:*:*:*:*:*:*
apache struts 2.5.1 cpe:2.3:a:apache:struts:2.5.1:*:*:*:*:*:*:*
apache struts 2.5.2 cpe:2.3:a:apache:struts:2.5.2:*:*:*:*:*:*:*
apache struts 2.5.3 cpe:2.3:a:apache:struts:2.5.3:*:*:*:*:*:*:*
apache struts 2.5.4 cpe:2.3:a:apache:struts:2.5.4:*:*:*:*:*:*:*
apache struts 2.5.5 cpe:2.3:a:apache:struts:2.5.5:*:*:*:*:*:*:*

References for CVE-2016-8738

cvelogic Threat Intelligence