CVE-2016-6816Tomcat Vulnerability
Improper Input Validation in Apache Tomcat
Published May 13, 2022 · Updated Jul 8, 2026 · Also known as DSA-3738-1, DSA-3739-1, GHSA-jc7p-5r39-9477, UBUNTU-CVE-2016-6816
Key Facts
Patch immediately- CVE-2016-6816 is a high-severity vulnerability (CVSS 7.1 v3.1) affecting Tomcat (Apache), tomcat6 (debian), tomcat7 (debian) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 40% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache-commons-dbcp 2.1.1-2.1, apache-commons-dbcp-javadoc 2.1.1-2.1, apache-commons-pool2 2.4.2-2.1.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v3.1
7.1
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
EPSS (30-day exploit likelihood)
40%
Higher than 98.6% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
43/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2016-6816
- advisoryhttps://ubuntu.com/security/CVE-2016-6816
- advisoryhttps://www.cve.org/CVERecord?id=CVE-2016-6816
- advisoryRHSA-2017:0244
- advisoryRHSA-2017:0245
- advisoryRHSA-2017:0246
Description
The code in Apache Tomcat 9.0.0.M1 to 9.0.0.M11, 8.5.0 to 8.5.6, 8.0.0.RC1 to 8.0.38, 7.0.0 to 7.0.72, and 6.0.0 to 6.0.47 that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response.
By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack and/or obtain sensitive information from requests other then their own.
Affected Products
626 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| TomcatApache | 6.0.0, 6.0.1, 6.0.10, 6.0.11, 6.0.12, 6.0.13, 6.0.14, 6.0.15 | 7.0.69-11.el7_3 |
| tomcat6debian | See advisory | 6.0.45+dfsg-1~deb7u3 |
| tomcat7debian | See advisory | 7.0.28-4+deb7u7 |
| tomcat8debian | See advisory | 8.0.14-1+deb8u5 |
| tomcat9debian | See advisory | 0 |
Patched Releases
apache-commons-dbcp
2.1.1-2.1
apache-commons-dbcp-javadoc
2.1.1-2.1
apache-commons-pool2
2.4.2-2.1
apache-commons-pool2-javadoc
2.4.2-2.1
apache-cxf
0:2.7.18-5.SP4_redhat_1.1.ep6.el5, 0:2.7.18-5.SP4_redhat_1.1.ep6.el6, 0:2.7.18-5.SP4_redhat_1.1.ep6.el7
Tomcat
NA, 0:7.0.69-11.el7_3, 7.0.69-11.el7_3, 7.0.78-7.13.4, 8.0.32-10.13.2, 8.0.32-11.1, 8.0.36-17.1, 8.0.36-4.1
tomcat-webapps
NA, 7.0.69-11.el7_3, 7.0.78-7.13.4, 8.0.32-10.13.2, 8.0.32-11.1, 8.0.36-17.1, 8.0.36-4.1
hibernate4-eap6
0:4.2.23-1.Final_redhat_1.1.ep6.el6, 0:4.2.23-1.Final_redhat_1.1.ep6.el7
hornetq
0:2.3.25-18.SP16_redhat_1.1.ep6.el5, 0:2.3.25-18.SP16_redhat_1.1.ep6.el6, 0:2.3.25-18.SP16_redhat_1.1.ep6.el7
infinispan
0:5.2.20-1.Final_redhat_1.1.ep6.el5, 0:5.2.20-1.Final_redhat_1.1.ep6.el6, 0:5.2.20-1.Final_redhat_1.1.ep6.el7
jbcs-httpd24
0:1-3.jbcs.el6, 0:1-3.jbcs.el7
jbcs-httpd24-apache-commons-daemon
0:1.0.15-1.redhat_2.1.jbcs.el6, 0:1.0.15-1.redhat_2.1.jbcs.el7
jbcs-httpd24-apache-commons-daemon-jsvc
1:1.0.15-17.redhat_2.jbcs.el6, 1:1.0.15-17.redhat_2.jbcs.el7
jboss-as-appclient
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-cli
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-client-all
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-clustering
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-cmp
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-configadmin
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-connector
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-console
0:2.5.15-1.Final_redhat_1.1.ep6.el5, 0:2.5.15-1.Final_redhat_1.1.ep6.el6, 0:2.5.15-1.Final_redhat_1.1.ep6.el7
jboss-as-controller
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-controller-client
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-core-security
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
jboss-as-deployment-repository
0:7.5.13-2.Final_redhat_2.1.ep6.el5, 0:7.5.13-2.Final_redhat_2.1.ep6.el6, 0:7.5.13-2.Final_redhat_2.1.ep6.el7
Timeline
Publicly disclosed
May 13, 2022
Last updated
Jul 8, 2026
Weakness Type
- CWE-20 Improper Input Validation
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
References
- advisorynvd.nist.gov · CVE-2016-6816
- advisoryubuntu.com · CVE-2016-6816
- advisorycve.org · CVERecord
- advisoryRHSA-2017:0244
- advisoryRHSA-2017:0245
FAQ
Common Questions.
The code in Apache Tomcat 9.0.0.M1 to 9.0.0.M11, 8.5.0 to 8.5.6, 8.0.0.RC1 to 8.0.38, 7.0.0 to 7.0.72, and 6.0.0 to 6.0.47 that parsed the HTTP request line permitted invalid characters.
Affected: Tomcat (Apache) versions 6.0.0, 6.0.1, 6.0.10, 6.0.11, 6.0.12, 6.0.13, 6.0.14, 6.0.15; tomcat6 (debian); tomcat7 (debian), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
A public exploit is reported by tracking sources, but no code link is listed yet.
Fixed versions are available, including apache-commons-dbcp 2.1.1-2.1, apache-commons-dbcp-javadoc 2.1.1-2.1, apache-commons-pool2 2.4.2-2.1.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
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