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Fencer Vulns
high 7.5

CVE-2016-6817 json

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

published 2017-08-10 9 y ago modified 2026-06-17 4 mo ago also GHSA-698c-2x4j-g9gq , EUVD-2022-2759

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
7.2%
EPSS 7.2% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.apache.tomcat:tomcat 8.5.8, 9.0.0.M12

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-6817 updated cvss 7.5

tomcat: Infinite loop in HTTP/2 header parser

  • Red Hat Software Collections rh-java-common-tomcat-lib, rh-java-common-tomcat-javadoc, rh-java-common-tomcat-el-2.2-api, rh-java-common-tomcat-jsp-2.2-api, rh-java-common-tomcat-servlet-3.0-api
    under investigation
  • Red Hat JBoss Enterprise Application Platform 5 tomcat Red Hat JBoss Enterprise Application Platform 6 tomcat Red Hat JBoss Enterprise Application Platform 7 tomcat Red Hat JBoss Enterprise Web Server 2 tomcat Red Hat JBoss Enterprise Web Server 3 tomcat Red Hat JBoss Web Server 3 tomcat8 tomcat8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

7.19% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.tomcat:tomcat
>=9.0.0.M1, <9.0.0.M12
>=8.5.0, <8.5.8
9.0.0.M12
8.5.8

Affected products

  • Apache Software Foundation Apache Tomcat

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.