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Fencer Vulns
high 7.5

CVE-2020-13935 in the critical feed json

Infinite Loop in Apache Tomcat

published 2020-07-14 6 y ago modified 2026-10-08 31 d ago also BIT-tomcat-2020-13935 , EUVD-2022-1098 , GHSA-m7jv-hq7h-mq7c

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
86.6%
EPSS 86.6% chance of exploitation in 30 days, percentile 99.7%
public exploits
0
none known

Summary

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 8.5.56 and 7.0.27 to 7.0.104. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service.

Patch / fix

  • maven org.apache.tomcat:tomcat 7.0.105, 8.5.57, 9.0.37, 10.0.0-M7
  • maven org.apache.tomcat.embed:tomcat-embed-websocket 7.0.105, 8.5.57, 9.0.37, 10.0.0-M7
  • maven org.apache.tomcat:tomcat-websocket 7.0.105, 8.5.57, 9.0.37, 10.0.0-M7
  • bitnami tomcat 7.0.105, 8.5.57, 9.0.37
  • oracle blockchain_platform 21.1.2
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.37-1

debian advisories DEBIAN-CVE-2020-13935

  • tomcat8 Ubuntu 16.04 LTS 8.0.32-1ubuntu1.13
  • tomcat9 Ubuntu 20.04 LTS 9.0.31-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2020-13935

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • jbossts jboss enterprise application platform 6 1:4.17.45-2.Final_redhat_2.1.ep6.el6
  • jbossweb jboss enterprise application platform 6 7.5.32-2.Final_redhat_1.2.ep6.el6
  • jboss-as-ee jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6
  • jboss-as-cli jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6
  • jboss-as-cmp jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6
  • jboss-as-jdr jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6
  • jboss-as-jmx jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6
  • jboss-as-jpa jboss enterprise application platform 6 7.5.24-2.Final_redhat_00001.1.ep6.el6

red hat advisories RHSA-2022:5459RHSA-2022:5460RHSA-2020:4004RHSA-2020:3303RHSA-2020:3383RHSA-2020:3306

  • tomcat SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES 12 SP3-LTSS +8 more 8.0.53-29.37.1
  • tomcat SLE Module for Web and Scripting 15 SP2 9.0.36-3.6.1
  • tomcat SLE Module for Web and Scripting 15 SP1 9.0.36-4.41.2
  • tomcat SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 9.0.36-3.65.2
  • tomcat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 9.0.36-3.45.1
  • tomcat SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 9.0.115-3.160.1

suse advisories SUSE-SU-2026:1058-1SUSE-SU-2020:2611-1SUSE-SU-2020:2047-1SUSE-SU-2020:2046-1SUSE-SU-2020:2045-1SUSE-SU-2020:2037-1

  • tomcat openSUSE Tumbleweed 9.0.43-8.1
  • tomcat10 openSUSE Tumbleweed 10.1.14-1.1
  • tomcat openSUSE Leap 15.2 9.0.36-lp152.2.4.1
  • tomcat openSUSE Leap 15.1 9.0.36-lp151.3.27.1

opensuse advisories openSUSE-SU-2024:12103-1openSUSE-SU-2024:13441-1openSUSE-SU-2020:1111-1openSUSE-SU-2020:1102-1

  • tomcat9 Arch Linux 9.0.37-1

arch linux advisories AVG-1205

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-2020-13935 updated cvss 7.5

tomcat: multiple requests with invalid payload length in a WebSocket frame could lead to DoS

  • Red Hat Enterprise Linux 8 pki-servlet-engine, pki-servlet-4.0-api
    affected: workaround, no fix available “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.”
  • Red Hat JBoss Data Grid 6 jbossweb jbossweb Red Hat JBoss Data Virtualization 6 jbossweb jbossweb Red Hat JBoss Fuse 6 tomcat Red Hat OpenStack Platform 10 (Newton) opendaylight Red Hat OpenStack Platform 13 (Queens) opendaylight 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
    affected: workaround, no fix planned “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.”
  • Red Hat EAP 6.4.24 release
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2022:5458
  • Red Hat Enterprise Linux Client (v. 7) tomcat 7.0.76-15.el7, tomcat-servlet-3.0-api 7.0.76-15.el7 Red Hat Enterprise Linux Client Optional (v. 7) tomcat 7.0.76-15.el7, tomcat-lib 7.0.76-15.el7, tomcat-jsvc 7.0.76-15.el7, tomcat-javadoc 7.0.76-15.el7, tomcat-webapps 7.0.76-15.el7, tomcat-el-2.2-api 7.0.76-15.el7, +3 more Red Hat Enterprise Linux ComputeNode (v. 7) tomcat 7.0.76-15.el7, tomcat-servlet-3.0-api 7.0.76-15.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) tomcat 7.0.76-15.el7, tomcat-lib 7.0.76-15.el7, tomcat-jsvc 7.0.76-15.el7, tomcat-javadoc 7.0.76-15.el7, tomcat-webapps 7.0.76-15.el7, tomcat-el-2.2-api 7.0.76-15.el7, +3 more Red Hat Enterprise Linux Server (v. 7) tomcat 7.0.76-15.el7, tomcat-lib 7.0.76-15.el7, tomcat-webapps 7.0.76-15.el7, tomcat-el-2.2-api 7.0.76-15.el7, tomcat-jsp-2.2-api 7.0.76-15.el7, tomcat-admin-webapps 7.0.76-15.el7, +1 more Red Hat Enterprise Linux Server Optional (v. 7) tomcat 7.0.76-15.el7, tomcat-lib 7.0.76-15.el7, tomcat-jsvc 7.0.76-15.el7, tomcat-javadoc 7.0.76-15.el7, tomcat-webapps 7.0.76-15.el7, tomcat-el-2.2-api 7.0.76-15.el7, +3 more
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 7) tomcat 7.0.76-15.el7, tomcat-lib 7.0.76-15.el7, tomcat-webapps 7.0.76-15.el7, tomcat-el-2.2-api 7.0.76-15.el7, tomcat-jsp-2.2-api 7.0.76-15.el7, tomcat-admin-webapps 7.0.76-15.el7, +1 more Red Hat Enterprise Linux Workstation Optional (v. 7) tomcat-jsvc 7.0.76-15.el7, tomcat-javadoc 7.0.76-15.el7, tomcat-docs-webapp 7.0.76-15.el7
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:4004
  • Red Hat Fuse 7.9
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2021:3140
  • Red Hat JBoss Enterprise Application Platform 6.4 async
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3382
  • Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 5 Server jbossweb 7.5.31-2.Final_redhat_2.1.ep6.el5 Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 6 Server jbossts 4.17.45-2.Final_redhat_2.1.ep6.el6, jbossweb 7.5.31-2.Final_redhat_2.1.ep6.el6, jbossweb 7.5.32-2.Final_redhat_1.2.ep6.el6, jboss-as-ee 7.5.24-2.Final_redhat_00001.1.ep6.el6, jboss-as-cli 7.5.24-2.Final_redhat_00001.1.ep6.el6, jboss-as-cmp 7.5.24-2.Final_redhat_00001.1.ep6.el6, +60 more Red Hat JBoss Enterprise Application Platform 6.4 for RHEL 7 Server jbossts 4.17.45-2.Final_redhat_2.1.ep6.el7, jbossweb 7.5.31-2.Final_redhat_2.1.ep6.el7, jbossweb 7.5.32-2.Final_redhat_1.2.ep6.el7, jboss-as-ee 7.5.24-2.Final_redhat_00001.1.ep6.el7, jboss-as-cli 7.5.24-2.Final_redhat_00001.1.ep6.el7, jboss-as-cmp 7.5.24-2.Final_redhat_00001.1.ep6.el7, +60 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3383
  • Red Hat JBoss Web Server (JWS) 5.3
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3308
show 5 more
  • Red Hat JBoss Web Server 3.1
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3305
  • Red Hat JBoss Web Server 3.1 for RHEL 6 tomcat7 7.0.70-41.ep7.el6, tomcat8 8.0.36-45.ep7.el6, tomcat7-lib 7.0.70-41.ep7.el6, tomcat8-lib 8.0.36-45.ep7.el6, tomcat7-jsvc 7.0.70-41.ep7.el6, tomcat8-jsvc 8.0.36-45.ep7.el6, +18 more Red Hat JBoss Web Server 3.1 for RHEL 7 tomcat7 7.0.70-41.ep7.el7, tomcat8 8.0.36-45.ep7.el7, tomcat7-lib 7.0.70-41.ep7.el7, tomcat8-lib 8.0.36-45.ep7.el7, tomcat7-jsvc 7.0.70-41.ep7.el7, tomcat8-jsvc 8.0.36-45.ep7.el7, +18 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3303
  • Red Hat JBoss Web Server 5.3 for RHEL 6 Server jws5-tomcat 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el6jws, +4 more Red Hat JBoss Web Server 5.3 for RHEL 7 Server jws5-tomcat 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el7jws, +4 more Red Hat JBoss Web Server 5.3 for RHEL 8 jws5-tomcat 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el8jws, +4 more
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3306
  • Red Hat Runtimes Spring Boot 2.2.6
    fixed: vendor fix “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.” RHSA-2020:3806
  • Red Hat Decision Manager 7 tomcat Red Hat Enterprise Linux 6 tomcat6, tomcat6-lib, tomcat6-log4j, tomcat6-javadoc, tomcat6-webapps, tomcat6-el-2.1-api, +4 more Red Hat Enterprise Linux 9 tomcat, tomcat-lib, tomcat-webapps, tomcat-el-3.0-api, tomcat-docs-webapp, tomcat-jsp-2.3-api, +2 more Red Hat Process Automation 7 tomcat
    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
31 d ago

Exploit prediction

86.61% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/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
OSV 3.1 7.5 CVSS:3.1/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
>=10.0.0-M1, <10.0.0-M7
>=9.0.0.M1, <9.0.37
>=8.5.0, <8.5.57
>=7.0.27, <7.0.105
10.0.0-M7
9.0.37
8.5.57
7.0.105
maven org.apache.tomcat.embed:tomcat-embed-websocket
>=7.0.27, <7.0.105
>=8.5.0, <8.5.57
>=9.0.0.M1, <9.0.37
>=10.0.0-M1, <10.0.0-M7
7.0.105
8.5.57
9.0.37
10.0.0-M7
maven org.apache.tomcat:tomcat-websocket
>=10.0.0-M1, <10.0.0-M7
>=9.0.0.M1, <9.0.37
>=8.5.0, <8.5.57
>=7.0.27, <7.0.105
10.0.0-M7
9.0.37
8.5.57
7.0.105
bitnami tomcat
>=7.0.27, <7.0.105
>=8.5.0, <8.5.57
>=9.0.1, <9.0.37
7.0.105
8.5.57
9.0.37

Affected products

  • n/a Apache Tomcat

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

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.