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Fencer Intel
high 7.3

CVE-2026-42498 json

Apache Tomcat: WebSocket authentication header exposure

published 5mo ago modified 14d ago also BIT-tomcat-2026-42498 , EUVD-2026-29515 , GHSA-fv25-8xcx-gqjc

cvss
7.3
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

Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability in Apache Tomcat.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109.

Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.

Patch / fix

  • maven org.apache.tomcat.embed:tomcat-embed-core 9.0.118, 10.1.55, 11.0.22
  • maven org.apache.tomcat:tomcat 9.0.118, 10.1.55, 11.0.22
  • maven org.apache.tomcat:tomcat-catalina 9.0.118, 10.1.55, 11.0.22
  • bitnami tomcat 9.0.118, 10.1.55, 11.0.22
  • apache tomcat-websocket 9.0.118, 10.1.55, 11.0.22
  • apache tomcat 9.0.118, 10.1.55, 11.0.22
  • org.apache.tomcat tomcat-websocket 9.0.118, 10.1.55, 11.0.22
  • apache tomcat-embed-websocket 9.0.118, 10.1.55, 11.0.22
  • org.apache.tomcat.embed tomcat-embed-websocket 9.0.118, 10.1.55, 11.0.22
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.70-2
  • tomcat10 Debian 12 10.1.55-1~deb12u1
  • tomcat10 Debian 13 10.1.55-1~deb13u1
  • tomcat10 Debian 14 10.1.55-1
  • tomcat11 Debian 13 11.0.22-1~deb13u1
  • tomcat11 Debian 14 11.0.22-1

debian advisories DEBIAN-CVE-2026-42498

  • tomcat9 Ubuntu 25.10 9.0.95-1ubuntu1.1
  • tomcat9 Ubuntu 26.04 LTS 9.0.115-1ubuntu0.1
  • tomcat10 Ubuntu 25.10 10.1.40-1ubuntu1.25.10.1
  • tomcat10 Ubuntu 26.04 LTS 10.1.40-1ubuntu1.26.04.1
  • tomcat9 Ubuntu Pro 18.04 LTS 9.0.16-3ubuntu0.18.04.2+esm8
  • tomcat9 Ubuntu Pro 20.04 LTS 9.0.31-1ubuntu0.9+esm3
  • tomcat9 Ubuntu Pro 22.04 LTS 9.0.58-1ubuntu0.2+esm4
  • tomcat9 Ubuntu Pro 24.04 LTS 9.0.70-2ubuntu0.1+esm3

ubuntu advisories UBUNTU-CVE-2026-42498

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

  • tomcat RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-lib RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-webapps RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-el-5.0-api RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-docs-webapp RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-jsp-3.1-api RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-admin-webapps RHEL 10.2 1:10.1.49-4.el10_2
  • tomcat-servlet-6.0-api RHEL 10.2 1:10.1.49-4.el10_2

red hat advisories RHSA-2026:69259RHSA-2026:68651RHSA-2026:68680RHSA-2026:68679RHSA-2026:68677RHSA-2026:68678

  • tomcat SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 9.0.118-150200.108.1
  • tomcat SLES for SAP applications 16.0, SLES 16.0 9.0.118-160000.1.1
  • tomcat10 SLES for SAP applications 16.0, SLES 16.0 10.1.55-160000.1.1
  • tomcat11 SLES for SAP applications 16.0, SLES 16.0 11.0.22-160000.1.1
  • tomcat10 SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES 15 SP6-LTSS +4 more 10.1.55-150200.5.67.1
  • tomcat11 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Web and Scripting 15 SP7 11.0.22-150600.13.21.1

suse advisories SUSE-SU-2026:2675-1SUSE-SU-2026:22195-1SUSE-SU-2026:22197-1SUSE-SU-2026:22196-1SUSE-SU-2026:2377-1SUSE-SU-2026:2374-1

  • tomcat openSUSE Leap 16.0 9.0.118-160000.1.1
  • tomcat11 openSUSE Leap 16.0 11.0.22-160000.1.1
  • tomcat10 openSUSE Leap 16.0 10.1.55-160000.1.1
  • tomcat openSUSE Tumbleweed 9.0.118-1.1
  • tomcat10 openSUSE Tumbleweed 10.1.55-1.1
  • tomcat11 openSUSE Tumbleweed 11.0.22-1.1

opensuse advisories openSUSE-SU-2026:21117-1openSUSE-SU-2026:21121-1openSUSE-SU-2026:21122-1openSUSE-SU-2026:10925-1openSUSE-SU-2026:10926-1openSUSE-SU-2026:10927-1

  • tomcat AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-lib AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-webapps AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-el-5.0-api AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-docs-webapp AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-jsp-3.1-api AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-admin-webapps AlmaLinux 10 1:10.1.49-4.el10_2.alma.1
  • tomcat-servlet-6.0-api AlmaLinux 10 1:10.1.49-4.el10_2.alma.1

almalinux advisories ALSA-2026:69259ALSA-2026:68651ALSA-2026:68660ALSA-2026:68677

  • tomcat Rocky Linux 10 1:10.1.49-4.el10_2
  • tomcat9 Rocky Linux 10 1:9.0.120-1.el10_2
  • tomcat Rocky Linux 9 1:9.0.120-2.el9_8
  • tomcat Rocky Linux 8 1:9.0.120-1.el8_10

rocky linux advisories RLSA-2026:69259RLSA-2026:68651RLSA-2026:68660RLSA-2026:68677

Is CVE-2026-42498 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2026-42498 updated cvss 6.5

tomcat-coyote: Apache Tomcat: Information disclosure due to HTTP Authentication Header exposure during WebSocket authentication.

  • Red Hat Certificate System 10 jss
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 tomcat6, tomcat6-lib, tomcat6-log4j, tomcat6-javadoc, tomcat6-webapps, tomcat6-el-2.1-api, +4 more
    affected: no fix available
  • Red Hat Enterprise Linux 7 tomcat, tomcat-lib, tomcat-jsvc, tomcat-javadoc, tomcat-webapps, tomcat-el-2.2-api, +4 more Red Hat Enterprise Linux 8 pki-servlet-engine, pki-servlet-4.0-api
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 jss, idm-jss, mod_proxy_cluster, pki-servlet-engine, pki-servlet-4.0-api
    affected: no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 10 jss, mod_proxy_cluster
    affected: no fix available, no fix planned “Out of support scope”
  • Red Hat Fuse 7 tomcat-coyote Red Hat JBoss Web Server 5 tomcat-coyote, jws5-mod_cluster, jws5-mod_cluster-tomcat
    affected: no fix planned “Out of support scope”
  • Red Hat OpenShift Dev Spaces devspaces/server-rhel9
    affected: no fix available “Fix deferred”
  • Red Hat Process Automation 7 tomcat-coyote Red Hat Single Sign-On 7 tomcat-coyote
    affected: no fix planned “Out of support scope”
show 16 more
  • 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 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 RHSA-2026:68660
  • Red Hat Enterprise Linux AppStream (v. 10) tomcat 10.1.49-4.el10_2, tomcat9 9.0.120-1.el10_2, tomcat-lib 10.1.49-4.el10_2, tomcat9-lib 9.0.120-1.el10_2, tomcat-webapps 10.1.49-4.el10_2, tomcat9-webapps 9.0.120-1.el10_2, +10 more
    fixed: vendor fix RHSA-2026:69259
  • 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 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 RHSA-2026:68678
  • 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 RHSA-2026:68679
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) tomcat 10.1.49-1.el10_0, tomcat9 9.0.120-1.el10_0, tomcat-lib 10.1.49-1.el10_0, tomcat9-lib 9.0.120-1.el10_0, tomcat-webapps 10.1.49-1.el10_0, tomcat9-webapps 9.0.120-1.el10_0, +10 more
    fixed: vendor fix RHSA-2026:67164
  • 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 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 RHSA-2026:68680
  • Red Hat Hardened Images tomcat10 10.1.55-1.hum1, tomcat11 11.0.22-0.1.hum1, tomcat10-lib 10.1.55-1.hum1, tomcat11-lib 11.0.22-0.1.hum1, tomcat10-common 10.1.55-1.hum1, tomcat10-webapps 10.1.55-1.hum1, +14 more
    fixed: vendor fix RHSA-2026:16528
  • 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 RHSA-2026:43401
  • Red Hat JBoss Web Server 6.2.4
    fixed: vendor fix 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 RHSA-2026:39188
  • Red Hat JBoss Web Server 7.0.0
    fixed: vendor fix RHSA-2026:39189
  • Red Hat JBoss Core Services jbcs-httpd24-mod_proxy_cluster, jbcs-httpd24-mod_cluster-native, jbcs-httpd24-mod_cluster-native-src-zip Red Hat JBoss Enterprise Application Platform Expansion Pack tomcat-coyote Red Hat JBoss Web Server 6 jws6-mod_cluster, jws6-mod_cluster-tomcat
    not affected: component not present
  • 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
5mo ago

Exploit prediction

0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
GitHub 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
OSV 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
maven org.apache.tomcat.embed:tomcat-embed-core
<9.0.118
>=10.1.0-M1, <10.1.55
>=11.0.0-M1, <11.0.22
9.0.118
10.1.55
11.0.22
maven org.apache.tomcat:tomcat
<9.0.118
>=10.1.0-M1, <10.1.55
>=11.0.0-M1, <11.0.22
9.0.118
10.1.55
11.0.22
maven org.apache.tomcat:tomcat-catalina
<9.0.118
>=10.1.0-M1, <10.1.55
>=11.0.0-M1, <11.0.22
9.0.118
10.1.55
11.0.22
bitnami tomcat
>=10.0.0, <10.1.55
>=11.0.0, <11.0.22
>=9.0.0, <9.0.118
10.1.55
11.0.22
9.0.118

Affected products

  • Apache Software Foundation Apache Tomcat

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel 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.