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Fencer Vulns
high 7.3

CVE-2026-55957 json

Apache Tomcat: Authentication bypass with JNDIRealm and GSSAPI authenticated bind

published 2026-06-29 4 mo ago modified 2026-11-04 4 d ago also BIT-tomcat-2026-55957 , EUVD-2026-40233 , GHSA-7895-gffq-w6jq

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.

Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

Patch / fix

  • maven org.apache.tomcat.embed:tomcat-embed-core 9.0.101, 10.1.37, 11.0.5
  • maven org.apache.tomcat:tomcat 9.0.101, 10.1.37, 11.0.5
  • maven org.apache.tomcat:tomcat-catalina 9.0.101, 10.1.37, 11.0.5
  • bitnami tomcat 9.0.101, 10.1.37, 11.0.5
  • apache tomcat 9.0.101, 10.1.37, 11.0.5
  • org.apache.tomcat tomcat 9.0.101, 10.1.37, 11.0.5
  • apache tomcat-catalina 9.0.101, 10.1.37, 11.0.5
  • org.apache.tomcat tomcat-catalina 9.0.101, 10.1.37, 11.0.5
  • apache tomcat-embed-core 9.0.101, 10.1.37, 11.0.5
  • org.apache.tomcat.embed tomcat-embed-core 9.0.101, 10.1.37, 11.0.5
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.70-2
  • tomcat10 Debian 12 10.1.52-1~deb12u1
  • tomcat10 Debian 13 10.1.52-1~deb13u1
  • tomcat10 Debian 14 10.1.40-1
  • tomcat11 Debian 13 11.0.15-1~deb13u1
  • tomcat11 Debian 14 11.0.5-1

debian advisories DEBIAN-CVE-2026-55957

  • tomcat RHEL 8 1:9.0.120-1.el8_10
  • tomcat-lib RHEL 8 1:9.0.120-1.el8_10
  • tomcat-webapps RHEL 8 1:9.0.120-1.el8_10
  • tomcat-el-3.0-api RHEL 8 1:9.0.120-1.el8_10
  • tomcat-docs-webapp RHEL 8 1:9.0.120-1.el8_10
  • tomcat-jsp-2.3-api RHEL 8 1:9.0.120-1.el8_10
  • tomcat-admin-webapps RHEL 8 1:9.0.120-1.el8_10
  • tomcat-servlet-4.0-api RHEL 8 1:9.0.120-1.el8_10

red hat advisories RHSA-2026:68680RHSA-2026:68679RHSA-2026:68677RHSA-2026:68678RHSA-2026:68659RHSA-2026:67163

  • tomcat AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-lib AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-webapps AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-el-3.0-api AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-docs-webapp AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-jsp-2.3-api AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-admin-webapps AlmaLinux 8 1:9.0.120-1.el8_10
  • tomcat-servlet-4.0-api AlmaLinux 8 1:9.0.120-1.el8_10

almalinux advisories ALSA-2026:68677

  • tomcat Rocky Linux 8 1:9.0.120-1.el8_10

rocky linux advisories RLSA-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-2026-55957 updated cvss 7.3

tomcat: Apache Tomcat: Authentication bypass via missing critical step in JNDIRealm GSSAPI configuration

  • 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 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 the affected package as soon as possible.”
  • 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.”
  • 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:68677
  • Red Hat Enterprise Linux AppStream (v. 9) tomcat 9.0.110-2.el9_8, tomcat-lib 9.0.110-2.el9_8, tomcat-webapps 9.0.110-2.el9_8, tomcat-el-3.0-api 9.0.110-2.el9_8, tomcat-docs-webapp 9.0.110-2.el9_8, tomcat-jsp-2.3-api 9.0.110-2.el9_8, +2 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 the affected package as soon as possible.” RHSA-2026:18916
  • Red Hat Enterprise Linux AppStream (v. 10) tomcat 10.1.49-1.el10, tomcat9 9.0.110-2.el10_2, tomcat-lib 10.1.49-1.el10, tomcat9-lib 9.0.110-2.el10_2, tomcat-webapps 10.1.49-1.el10, tomcat-el-5.0-api 10.1.49-1.el10, +10 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 the affected package as soon as possible.” RHSA-2026:18537
  • 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:68679
show 7 more
  • 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” 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 “Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.” RHSA-2026:29203
  • Red Hat Enterprise Linux 6 tomcat6, tomcat6-lib, tomcat6-log4j, tomcat6-javadoc, tomcat6-webapps, tomcat6-el-2.1-api, +4 more
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 pki-servlet-engine, pki-servlet-4.0-api
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux 9 pki-servlet-engine, pki-servlet-4.0-api
    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
total
Assessed
4 mo ago

Exploit prediction

2.85% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

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
>=11.0.0-M1, <11.0.5
>=10.1.0-M1, <10.1.37
>=9.0.0.M1, <9.0.101
>=8.5.0, <=8.5.100
<=7.0.109
11.0.5
10.1.37
9.0.101
maven org.apache.tomcat:tomcat
>=11.0.0-M1, <11.0.5
>=10.1.0-M1, <10.1.37
>=9.0.0.M1, <9.0.101
>=8.5.0, <=8.5.100
<=7.0.109
11.0.5
10.1.37
9.0.101
maven org.apache.tomcat:tomcat-catalina
>=11.0.0-M1, <11.0.5
>=10.1.0-M1, <10.1.37
>=9.0.0.M1, <9.0.101
>=8.5.0, <=8.5.100
<=7.0.109
11.0.5
10.1.37
9.0.101
bitnami tomcat
<9.0.101
>=10.0.0, <10.1.37
>=11.0.0, <11.0.5
9.0.101
10.1.37
11.0.5

Affected products

  • Apache Software Foundation Apache Tomcat

Classification

Weakness
  • CWE-304 Missing Critical Step in Authentication

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.