--- id: CVE-2026-55955 title: >- Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55,… summary: >- Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55,… severity: medium cvss: 6.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N' cwe: - CWE-287 - CWE-294 vendor: apache product: tomcat affected: - tomcat < 9.0.19 - 'tomcat >= 10.1.0, < 10.1.56' - 'tomcat >= 11.0.0, < 11.0.23' patched: - tomcat 11.0.23 published: '2026-06-29' updated: '2026-07-02' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55955' references: - url: 'https://lists.apache.org/thread/g4p5sf45p3f9r011pwqs9r54yd64s106' label: security@apache.org - url: 'http://www.openwall.com/lists/oss-security/2026/06/29/24' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55955.json - url: 'https://access.redhat.com/security/cve/CVE-2026-55955' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2494678' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-55955' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55955' - url: 'https://access.redhat.com/errata/RHSA-2026:67163' - url: 'https://access.redhat.com/errata/RHSA-2026:68651' - url: 'https://access.redhat.com/errata/RHSA-2026:68677' - url: 'https://access.redhat.com/errata/RHSA-2026:68680' - url: 'https://access.redhat.com/errata/RHSA-2026:68678' - url: 'https://access.redhat.com/errata/RHSA-2026:68679' - url: 'https://access.redhat.com/errata/RHSA-2026:68659' - url: 'https://access.redhat.com/errata/RHSA-2026:68660' - url: 'https://access.redhat.com/errata/RHSA-2026:29203' - url: 'https://access.redhat.com/errata/RHSA-2026:32960' tags: - nvd - csaf - vex - red-hat - score-dispute epss: 0.00436 epssPercentile: 0.35213 ingestedAt: '2026-07-03T13:02:28.104Z' scores: nvd: 6.5 vendor: 4.2 --- ## Overview Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109. Users are recommended to upgrade to version 11.0.23, 10.1.56, 9.0.119, which fixes the issue. ## Affected - `tomcat < 9.0.19` - `tomcat >= 10.1.0, < 10.1.56` - `tomcat >= 11.0.0, < 11.0.23` ## Remediation Upgrade past the affected range: - `tomcat 11.0.23` ## Vendor advisories - **RHSA-2026:67163** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67163) - **RHSA-2026:68651** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-09-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:68651) - **RHSA-2026:68677** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68677) - **RHSA-2026:68680** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68680) - **RHSA-2026:68678** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68678) - **RHSA-2026:68679** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68679) - **RHSA-2026:68659** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68659) - **RHSA-2026:68660** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68660) - **RHSA-2026:29203** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:29203) - **RHSA-2026:32960** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:32960) - **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat JBoss Web Server 5 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55955.json)