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NVD / CVE Program· CNA apache

CVE-2020-13934: 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…

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Plan (action score 49/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 64.1% (FIRST EPSS); higher than 99.2% of all records.
  • 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.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: tomcat9 (Debian:10) 9.0.31-1~deb10u2; tomcat9 (Debian:12) 9.0.37-1; tomcat8 (Debian:9) 8.5.54-0+deb9u3.
  • Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Add it to your regular patch cycle. Upgrade to tomcat9 (Debian:10) 9.0.31-1~deb10u2; tomcat9 (Debian:12) 9.0.37-1; tomcat8 (Debian:9) 8.5.54-0+deb9u3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Jul 14, 2020
Updated
Oct 8, 2026
EPSS
64.1% · 99th percentile

Report tools

JSON

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%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-13934

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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

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
Affected versions · NVD (20)

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

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

Same product

apache: all records

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…KEV
    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

Published before and after this one in the same product

  • ← EarlierCVE-2020-9484May 20, 2020 · When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is…
    45Plan
  • ← EarlierCVE-2020-11996Jun 26, 2020 · A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could…
    38Monitor
  • Later →CVE-2020-13935Jul 14, 2020 · The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.
    56Plan

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.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

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.

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records