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Fencer Vulns
medium 6.5

CVE-2026-55956 json

Apache Tomcat: Security constraints for default servlet ignored method

published 2026-06-29 4 mo ago modified 2026-11-04 4 d ago also BIT-tomcat-2026-55956 , EUVD-2026-40232 , GHSA-5v3h-fjv2-54fg

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 53%
public exploits
0
none known

Summary

Improper Authorization vulnerability in Apache Tomcat leads to security constraints specified for the default servlet ignoring any method or method omission configured as part of the constraint.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fix the issue.

Patch / fix

  • maven org.apache.tomcat.embed:tomcat-embed-core 9.0.119, 10.1.56, 11.0.23
  • maven org.apache.tomcat:tomcat 9.0.119, 10.1.56, 11.0.23
  • maven org.apache.tomcat:tomcat-catalina 9.0.119, 10.1.56, 11.0.23
  • bitnami tomcat 9.0.119, 10.1.56, 11.0.23
  • apache tomcat 9.0.119, 10.1.56, 11.0.23
  • org.apache.tomcat tomcat 9.0.119, 10.1.56, 11.0.23
  • apache tomcat-catalina 9.0.119, 10.1.56, 11.0.23
  • org.apache.tomcat tomcat-catalina 9.0.119, 10.1.56, 11.0.23
  • apache tomcat-embed-core 9.0.119, 10.1.56, 11.0.23
  • org.apache.tomcat.embed tomcat-embed-core 9.0.119, 10.1.56, 11.0.23
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.70-2
  • tomcat10 Debian 14 10.1.60-1
  • tomcat11 Debian 14 11.0.24-1

debian advisories DEBIAN-CVE-2026-55956

  • tomcat9 RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-lib RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-webapps RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-el-3.0-api RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-docs-webapp RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-jsp-2.3-api RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-admin-webapps RHEL 10.2 1:9.0.120-1.el10_2
  • tomcat9-servlet-4.0-api RHEL 10.2 1:9.0.120-1.el10_2

red hat advisories RHSA-2026:68651RHSA-2026:68680RHSA-2026:68679RHSA-2026:68677RHSA-2026:68678RHSA-2026:68660

  • tomcat10 SLE Module for Web and Scripting 15 SP7 10.1.56-150200.5.70.1
  • tomcat SLE Module for Web and Scripting 15 SP7 9.0.119-150200.111.1
  • tomcat11 SLE Module for Web and Scripting 15 SP7 11.0.23-150600.13.24.1
  • tomcat10 SLES for SAP applications 16.0, SLES 16.0 10.1.56-160000.1.1
  • tomcat SLES for SAP applications 16.0, SLES 16.0 9.0.119-160000.1.1
  • tomcat11 SLES for SAP applications 16.0, SLES 16.0 11.0.23-160000.1.1
  • tomcat SLES LTSS Extended Security 12 SP5 9.0.119-3.169.1

suse advisories SUSE-SU-2026:3167-1SUSE-SU-2026:3112-1SUSE-SU-2026:3088-1SUSE-SU-2026:3087-1SUSE-SU-2026:22647-1SUSE-SU-2026:22646-1

  • tomcat openSUSE Leap 16.0 9.0.119-160000.1.1
  • tomcat10 openSUSE Leap 16.0 10.1.56-160000.1.1
  • tomcat11 openSUSE Leap 16.0 11.0.23-160000.1.1
  • tomcat openSUSE Tumbleweed 9.0.119-1.1
  • tomcat10 openSUSE Tumbleweed 10.1.56-1.1
  • tomcat11 openSUSE Tumbleweed 11.0.23-1.1

opensuse advisories openSUSE-SU-2026:21327-1openSUSE-SU-2026:21328-1openSUSE-SU-2026:21329-1openSUSE-SU-2026:11208-1openSUSE-SU-2026:11209-1openSUSE-SU-2026:11195-1

  • tomcat9 AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-lib AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-webapps AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-el-3.0-api AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-docs-webapp AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-jsp-2.3-api AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-admin-webapps AlmaLinux 10 1:9.0.120-1.el10_2.alma.1
  • tomcat9-servlet-4.0-api AlmaLinux 10 1:9.0.120-1.el10_2.alma.1

almalinux advisories ALSA-2026:68651ALSA-2026:68660ALSA-2026:68677

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-2026-55956 updated cvss 6.5

tomcat: Apache Tomcat: Improper Authorization Allows Security Constraint Bypass

  • 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 7 tomcat, tomcat-lib, tomcat-jsvc, tomcat-javadoc, tomcat-webapps, tomcat-el-2.2-api, +4 more
    affected: workaround, no fix planned “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).”
  • Red Hat Enterprise Linux 8 pki-servlet-engine, pki-servlet-4.0-api Red Hat Enterprise Linux 9 pki-servlet-engine, pki-servlet-4.0-api Red Hat Enterprise Linux 10 tomcat
    affected: workaround, no fix available “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).”
  • Red Hat JBoss Web Server 5 jws5-tomcat, jws5-tomcat-lib, jws5-tomcat-jsvc, jws5-tomcat-javadoc, jws5-tomcat-selinux, jws5-tomcat-webapps, +7 more
    affected: workaround, no fix planned “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).”
  • Red Hat Enterprise Linux AppStream (v. 8) tomcat 9.0.120-1.el8_10, tomcat-lib 9.0.120-1.el8_10, tomcat-webapps 9.0.120-1.el8_10, tomcat-el-3.0-api 9.0.120-1.el8_10, tomcat-docs-webapp 9.0.120-1.el8_10, tomcat-jsp-2.3-api 9.0.120-1.el8_10, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68677
  • Red Hat Enterprise Linux AppStream (v. 9) tomcat 9.0.120-2.el9_8, tomcat-lib 9.0.120-2.el9_8, tomcat-webapps 9.0.120-2.el9_8, tomcat-el-3.0-api 9.0.120-2.el9_8, tomcat-docs-webapp 9.0.120-2.el9_8, tomcat-jsp-2.3-api 9.0.120-2.el9_8, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68660
  • Red Hat Enterprise Linux AppStream (v. 10) tomcat9 9.0.120-1.el10_2, tomcat9-lib 9.0.120-1.el10_2, tomcat9-webapps 9.0.120-1.el10_2, tomcat9-el-3.0-api 9.0.120-1.el10_2, tomcat9-docs-webapp 9.0.120-1.el10_2, tomcat9-jsp-2.3-api 9.0.120-1.el10_2, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68651
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) tomcat 9.0.120-1.el8_8, tomcat-lib 9.0.120-1.el8_8, tomcat-webapps 9.0.120-1.el8_8, tomcat-el-3.0-api 9.0.120-1.el8_8, tomcat-docs-webapp 9.0.120-1.el8_8, tomcat-jsp-2.3-api 9.0.120-1.el8_8, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68680
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) tomcat 9.0.120-1.el9_2, tomcat-lib 9.0.120-1.el9_2, tomcat-webapps 9.0.120-1.el9_2, tomcat-el-3.0-api 9.0.120-1.el9_2, tomcat-docs-webapp 9.0.120-1.el9_2, tomcat-jsp-2.3-api 9.0.120-1.el9_2, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68678
show 10 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) tomcat 9.0.120-1.el9_4, tomcat-lib 9.0.120-1.el9_4, tomcat-webapps 9.0.120-1.el9_4, tomcat-el-3.0-api 9.0.120-1.el9_4, tomcat-docs-webapp 9.0.120-1.el9_4, tomcat-jsp-2.3-api 9.0.120-1.el9_4, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68679
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) tomcat9 9.0.120-1.el10_0, tomcat9-lib 9.0.120-1.el10_0, tomcat9-webapps 9.0.120-1.el10_0, tomcat9-el-3.0-api 9.0.120-1.el10_0, tomcat9-docs-webapp 9.0.120-1.el10_0, tomcat9-jsp-2.3-api 9.0.120-1.el10_0, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:67163
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) tomcat 9.0.120-1.el9_6, tomcat-lib 9.0.120-1.el9_6, tomcat-webapps 9.0.120-1.el9_6, tomcat-el-3.0-api 9.0.120-1.el9_6, tomcat-docs-webapp 9.0.120-1.el9_6, tomcat-jsp-2.3-api 9.0.120-1.el9_6, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68659
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) tomcat 9.0.120-1.el8_8, tomcat-lib 9.0.120-1.el8_8, tomcat-webapps 9.0.120-1.el8_8, tomcat-el-3.0-api 9.0.120-1.el8_8, tomcat-docs-webapp 9.0.120-1.el8_8, tomcat-jsp-2.3-api 9.0.120-1.el8_8, +2 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:68680
  • Red Hat Hardened Images tomcat10 10.1.56-1.hum1, tomcat11 11.0.23-0.1.hum1, tomcat10-lib 10.1.56-1.hum1, tomcat11-lib 11.0.23-0.1.hum1, tomcat10-common 10.1.56-1.hum1, tomcat10-webapps 10.1.56-1.hum1, +14 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:29203
  • Red Hat JBoss Web Server 6.2 on RHEL 8 jws6-tomcat 10.1.49-15.redhat_00013.1.el8jws, jws6-tomcat-lib 10.1.49-15.redhat_00013.1.el8jws, jws6-tomcat-javadoc 10.1.49-15.redhat_00013.1.el8jws, jws6-tomcat-selinux 10.1.49-15.redhat_00013.1.el8jws, jws6-tomcat-webapps 10.1.49-15.redhat_00013.1.el8jws, jws6-tomcat-el-5.0-api 10.1.49-15.redhat_00013.1.el8jws, +4 more Red Hat JBoss Web Server 6.2 on RHEL 9 jws6-tomcat 10.1.49-15.redhat_00013.1.el9jws, jws6-tomcat-lib 10.1.49-15.redhat_00013.1.el9jws, jws6-tomcat-javadoc 10.1.49-15.redhat_00013.1.el9jws, jws6-tomcat-selinux 10.1.49-15.redhat_00013.1.el9jws, jws6-tomcat-webapps 10.1.49-15.redhat_00013.1.el9jws, jws6-tomcat-el-5.0-api 10.1.49-15.redhat_00013.1.el9jws, +4 more Red Hat JBoss Web Server 6.2 on RHEL 10 jws6-tomcat 10.1.49-15.redhat_00013.1.el10jws, jws6-tomcat-lib 10.1.49-15.redhat_00013.1.el10jws, jws6-tomcat-javadoc 10.1.49-15.redhat_00013.1.el10jws, jws6-tomcat-selinux 10.1.49-15.redhat_00013.1.el10jws, jws6-tomcat-webapps 10.1.49-15.redhat_00013.1.el10jws, jws6-tomcat-el-5.0-api 10.1.49-15.redhat_00013.1.el10jws, +4 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:43401
  • Red Hat JBoss Web Server 6.2.4
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:43402
  • Red Hat JBoss Web Server 7.0 on RHEL 8 jws7-tomcat 11.0.21-5.redhat_00004.1.el8jws, jws7-tomcat-lib 11.0.21-5.redhat_00004.1.el8jws, jws7-tomcat-javadoc 11.0.21-5.redhat_00004.1.el8jws, jws7-tomcat-selinux 11.0.21-5.redhat_00004.1.el8jws, jws7-tomcat-webapps 11.0.21-5.redhat_00004.1.el8jws, jws7-tomcat-el-5.0-api 11.0.21-5.redhat_00004.1.el8jws, +4 more Red Hat JBoss Web Server 7.0 on RHEL 9 jws7-tomcat 11.0.21-5.redhat_00004.1.el9jws, jws7-tomcat-lib 11.0.21-5.redhat_00004.1.el9jws, jws7-tomcat-javadoc 11.0.21-5.redhat_00004.1.el9jws, jws7-tomcat-selinux 11.0.21-5.redhat_00004.1.el9jws, jws7-tomcat-webapps 11.0.21-5.redhat_00004.1.el9jws, jws7-tomcat-el-5.0-api 11.0.21-5.redhat_00004.1.el9jws, +4 more Red Hat JBoss Web Server 7.0 on RHEL 10 jws7-tomcat 11.0.21-5.redhat_00004.1.el10jws, jws7-tomcat-lib 11.0.21-5.redhat_00004.1.el10jws, jws7-tomcat-javadoc 11.0.21-5.redhat_00004.1.el10jws, jws7-tomcat-selinux 11.0.21-5.redhat_00004.1.el10jws, jws7-tomcat-webapps 11.0.21-5.redhat_00004.1.el10jws, jws7-tomcat-el-5.0-api 11.0.21-5.redhat_00004.1.el10jws, +4 more
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:39188
  • Red Hat JBoss Web Server 7.0.0
    fixed: vendor fix “Review your application's web.xml file. Ensure security constraints explicitly deny unauthorized users by path, rather than relying strictly on filtering specific HTTP methods (like GET or POST).” RHSA-2026:39189
  • Red Hat JBoss Web Server 7.0 on RHEL 8 jws7-build 1-1.el8jws, jws7-runtime 1-1.el8jws, jws7-javapackages-tools 6.0.0-1.el8jws, jws7-ecj 4.38.0-1.redhat_00001.1.el8jws, jws7-python3-javapackages 6.0.0-1.el8jws, jws7-tomcat-native 1.3.7-2.redhat_2.el8jws, +6 more Red Hat JBoss Web Server 7.0 on RHEL 9 jws7-build 1-1.el9jws, jws7-runtime 1-1.el9jws, jws7-javapackages-tools 6.0.0-1.el9jws, jws7-ecj 4.38.0-1.redhat_00001.1.el9jws, jws7-python3-javapackages 6.0.0-1.el9jws, jws7-tomcat-native 1.3.7-2.redhat_2.el9jws, +6 more Red Hat JBoss Web Server 7.0 on RHEL 10 jws7-build 1-1.el10jws, jws7-runtime 1-1.el10jws, jws7-javapackages-tools 6.0.0-1.el10jws, jws7-ecj 4.38.0-1.redhat_00001.1.el10jws, jws7-python3-javapackages 6.0.0-1.el10jws, jws7-tomcat-native 1.3.7-2.redhat_2.el10jws, +6 more
    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
4 mo ago

Exploit prediction

0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.tomcat.embed:tomcat-embed-core
>=11.0.0-M1, <11.0.23
>=10.1.0-M1, <10.1.56
>=9.0.0.M1, <9.0.119
>=8.5.0, <=8.5.100
<=7.0.109
11.0.23
10.1.56
9.0.119
maven org.apache.tomcat:tomcat
>=11.0.0-M1, <11.0.23
>=10.1.0-M1, <10.1.56
>=9.0.0.M1, <9.0.119
>=8.5.0, <=8.5.100
<=7.0.109
11.0.23
10.1.56
9.0.119
maven org.apache.tomcat:tomcat-catalina
>=11.0.0-M1, <11.0.23
>=10.1.0-M1, <10.1.56
>=9.0.0.M1, <9.0.119
>=8.5.0, <=8.5.100
<=7.0.109
11.0.23
10.1.56
9.0.119
bitnami tomcat
<9.0.119
>=10.0.0, <10.1.56
>=11.0.0, <11.0.23
9.0.119
10.1.56
11.0.23

Affected products

  • Apache Software Foundation Apache Tomcat

Classification

Weakness

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.