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CVE-2020-13934· NVD / CVE Program· CNA apache

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 proces

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jul 14, 2020
Updated
Aug 25, 2026
EPSS
64.1% · 99th percentile
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Action score

49

Plan

Add it to your regular patch cycle.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
19 / 30 · 64.1%

Affected systems

VendorProduct
apachetomcat
debiandebian linux
netapponcommand system manager
opensuseleap
canonicalubuntu linux
oracleagile engineering data management
oracleagile product lifecycle management
oraclecommunications instant messaging server
oraclefmw platform
oracleinstantis enterprisetrack
oraclemanaged file transfer
oraclemysql enterprise monitor

and 2 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache tomcat8.5.1 and later · up to 8.5.56 inclusive
  • apache tomcat9.0.1 and later · up to 9.0.36 inclusive
  • apache tomcat10.0.0
  • apache tomcat9.0.0
  • canonical ubuntu linux20.04
  • debian debian linux10.0
  • debian debian linux9.0
  • netapp oncommand system manager3.0.0 and later · up to 3.1.3 inclusive
  • opensuse leap15.1
  • opensuse leap15.2
  • oracle agile engineering data management6.2.1.0
  • oracle agile product lifecycle management9.3.3
  • oracle agile product lifecycle management9.3.5
  • oracle agile product lifecycle management9.3.6
  • oracle communications instant messaging server10.0.1.5.0
  • oracle fmw platform12.2.1.3.0
  • oracle fmw platform12.2.1.4.0
  • oracle instantis enterprisetrack17.1
  • oracle instantis enterprisetrack17.2
  • oracle instantis enterprisetrack17.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a Apache Tomcat

    • Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36, 8.5.1 to 8.5.56affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:10tomcat9before 9.0.31-1~deb10u29.0.31-1~deb10u2
Debian:12tomcat9before 9.0.37-19.0.37-1
Debian:9tomcat8before 8.5.54-0+deb9u38.5.54-0+deb9u3
Mavenorg.apache.tomcat:tomcatfrom 10.0.0-M1 · before 10.0.0-M610.0.0-M6
Mavenorg.apache.tomcat:tomcatfrom 8.5.1 · before 8.5.568.5.56
Mavenorg.apache.tomcat:tomcatfrom 9.0.0.M5 · before 9.0.369.0.36
Mavenorg.apache.tomcat:tomcat-coyotefrom 10.0.0-M1 · before 10.0.0-M610.0.0-M6
Mavenorg.apache.tomcat:tomcat-coyotefrom 8.5.1 · before 8.5.568.5.56
Mavenorg.apache.tomcat:tomcat-coyotefrom 9.0.0.M5 · before 9.0.369.0.36
openSUSE:Leap 15.1tomcatbefore 9.0.36-lp151.3.27.19.0.36-lp151.3.27.1
openSUSE:Leap 15.2tomcatbefore 9.0.36-lp152.2.4.19.0.36-lp152.2.4.1
openSUSE:Tumbleweedtomcatbefore 9.0.43-8.19.0.43-8.1
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcatbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-admin-webappsbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-docs-webappbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-el-3.0-apibefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-javadocbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-jsp-2.3-apibefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-libbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-selinuxbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-servlet-4.0-apibefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el6jws5-tomcat-webappsbefore 0:9.0.30-5.redhat_6.1.el6jws0:9.0.30-5.redhat_6.1.el6jws
Red Hat:jboss_enterprise_web_server:5.3::el7jws5-tomcatbefore 0:9.0.30-5.redhat_6.1.el7jws0:9.0.30-5.redhat_6.1.el7jws
Red Hat:jboss_enterprise_web_server:5.3::el7jws5-tomcat-admin-webappsbefore 0:9.0.30-5.redhat_6.1.el7jws0:9.0.30-5.redhat_6.1.el7jws

+23

Other highest-scoring records for the same primary product.

  • CVE-2025-24813Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUTKEV
    99Now
  • CVE-2016-8735Remote code execution is possible with Apache Tomcat before 6.0.48, 7.x before 7.0.73, 8.x before 8.0.39, 8.5.x before 8.5.7, and 9.x beforeKEV
    96Now
  • CVE-2017-12617When running Apache Tomcat versions 9.0.0.M1 to 9.0.0, 8.5.0 to 8.5.22, 8.0.0.RC1 to 8.0.46 and 7.0.0 to 7.0.81 with HTTP PUTs enabled (e.g.KEV
    92Now
  • CVE-2017-12615When running Apache Tomcat 7.0.0 to 7.0.79 on Windows with HTTP PUTs enabled (e.g.KEV
    92Now
  • CVE-2026-34486Apache Tomcat: Fix for CVE-2026-29146 allowed bypass of EncryptInterceptorKEV
    62This week
  • CVE-2019-0232When running on Windows with enableCmdLineArguments enabled, the CGI Servlet in Apache Tomcat 9.0.0.M1 to 9.0.17, 8.5.0 to 8.5.39 and 7.0.0
    62This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Debian:tomcat88.5.54-0+deb9u3 · Debian:9Package registry (OSV)
Debian:tomcat99.0.37-1 · Debian:12Package registry (OSV)
Maven:org.apache.tomcat:tomcat10.0.0-M6Package registry (OSV)
Maven:org.apache.tomcat:tomcat8.5.56Package registry (OSV)
Maven:org.apache.tomcat:tomcat9.0.36Package registry (OSV)
Maven:org.apache.tomcat:tomcat-coyote10.0.0-M6Package registry (OSV)
Maven:org.apache.tomcat:tomcat-coyote8.5.56Package registry (OSV)
Maven:org.apache.tomcat:tomcat-coyote9.0.36Package registry (OSV)
openSUSE:tomcat9.0.36-lp151.3.27.1 · openSUSE:Leap 15.1Package registry (OSV)
Red Hat:jws5-tomcat0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-admin-webapps0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-docs-webapp0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-el-3.0-api0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-javadoc0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-jsp-2.3-api0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-lib0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-selinux0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-servlet-4.0-api0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
Red Hat:jws5-tomcat-webapps0:9.0.30-5.redhat_6.1.el6jws · Red Hat:jboss_enterprise_web_server:5.3::el6Package registry (OSV)
SUSE:tomcat9.0.36-3.45.1 · SUSE:OpenStack Cloud 9Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

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References

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