CVE-2016-6817

Improper Restriction of Operations within the Bounds of a Memory Buffer in Apache Tomcat

7.5 HighFix available

The HTTP/2 header parser in Apache Tomcat 9.0.0.M1 to 9.0.0.M11 and 8.5.0 to 8.5.6 entered an infinite loop if a header was received that was larger than the available buffer. This made a denial of service attack possible.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

7.19%Up 5.3 points since Feb 4, 2022

What each source reports

CVE List 7.5

Record: CVE-2016-6817
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-835
Updated: 2026-11-02

EUVDEUVD-2022-2759 7.5

Record: EUVD-2022-2759
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-698c-2x4j-g9gq 7.5

Improper Restriction of Operations within the Bounds of a Memory Buffer in Apache Tomcat

Record: GHSA-698c-2x4j-g9gq
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-119, CWE-835
Updated: 2026-11-02

NVD 7.5

Record: CVE-2016-6817
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-119, CWE-835
Updated: 2026-11-02

OSV 7.5

Record: CVE-2016-6817
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVGHSA-698c-2x4j-g9gq 7.5

Improper Restriction of Operations within the Bounds of a Memory Buffer in Apache Tomcat

Record: GHSA-698c-2x4j-g9gq
CVSS 3.0: 7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-119, CWE-835
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`org.apache.tomcat:tomcat` Maven	9.0.0.M1 to 9.0.0.M11	9.0.0.M12
`org.apache.tomcat:tomcat` Maven	8.5.0 up to 8.5.8	8.5.8
`org.apache.tomcat:tomcat` Maven	9.0.0.M1 up to 9.0.0.M12, plus listed versions 9.0.0.M109.0.0.M119.0.0.M39.0.0.M49.0.0.M69.0.0.M89.0.0.M9	9.0.0.M12
`org.apache.tomcat:tomcat` Maven	8.5.0 up to 8.5.8, plus listed versions 8.5.28.5.38.5.48.5.58.5.6	8.5.8

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2016-6817 is a high vulnerability (CVSS 7.5) in Apache Tomcat, published August 10, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 7.19%, the 94th percentile. Fixed in org.apache.tomcat:tomcat 9.0.0.M12.

References

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