Vulnerability-Lookup

RHSA-2026:44427

Vulnerability from csaf_redhat - Published: 2026-07-23 11:17 - Updated: 2026-08-16 05:44

Summary

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Severity

Moderate

Notes

Topic: An update for Red Hat Hardened Images RPMs is now available.

Details: This update includes the following RPMs: tomcat11: * tomcat11-11.0.24-0.2.hum1 (noarch) * tomcat11-admin-webapps-11.0.24-0.2.hum1 (noarch) * tomcat11-common-11.0.24-0.2.hum1 (noarch) * tomcat11-docs-webapp-11.0.24-0.2.hum1 (noarch) * tomcat11-el-6.0-api-11.0.24-0.2.hum1 (noarch) * tomcat11-jsp-4.0-api-11.0.24-0.2.hum1 (noarch) * tomcat11-lib-11.0.24-0.2.hum1 (noarch) * tomcat11-servlet-6.1-api-11.0.24-0.2.hum1 (noarch) * tomcat11-user-instance-11.0.24-0.2.hum1 (noarch) * tomcat11-webapps-11.0.24-0.2.hum1 (noarch) * tomcat11-11.0.24-0.2.hum1.src (src)

Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.

CVE-2026-43513

In Apache Tomcat, LockOutRealm mishandled case sensitivity in usernames, resulting in less effective blocking of brute force attacks.

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWE-178 - Improper Handling of Case Sensitivity

Affected products

Fixed 2 products

Product	Identifier	Version	Remediation
Unresolved product id: Red Hat Hardened Images:tomcat11-main@noarch		—	Vendor Fix fix Workaround
Unresolved product id: Red Hat Hardened Images:tomcat11-main@src		—	Vendor Fix fix Workaround

Threats

Impact Moderate

References

10 references

URL	Category
https://access.redhat.com/errata/RHSA-2026:44427	self
https://images.redhat.com/	external
https://access.redhat.com/security/cve/CVE-2026-43513	external
https://access.redhat.com/security/updates/classi…	external
https://security.access.redhat.com/data/csaf/v2/a…	self
https://access.redhat.com/security/cve/CVE-2026-43513	self
https://bugzilla.redhat.com/show_bug.cgi?id=2476520	external
https://www.cve.org/CVERecord?id=CVE-2026-43513	external
https://nvd.nist.gov/vuln/detail/CVE-2026-43513	external
https://lists.apache.org/thread/ytjcgldshj73lcnd1…	external

JSON

To clipboard

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        "text": "This update includes the following RPMs:\n\ntomcat11:\n  * tomcat11-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-admin-webapps-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-common-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-docs-webapp-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-el-6.0-api-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-jsp-4.0-api-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-lib-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-servlet-6.1-api-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-user-instance-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-webapps-11.0.24-0.2.hum1 (noarch)\n  * tomcat11-11.0.24-0.2.hum1.src (src)",
        "title": "Details"
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        "name": "Improper Handling of Case Sensitivity"
      },
      "discovery_date": "2026-05-12T16:01:48.767743+00:00",
      "ids": [
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          "text": "In Apache Tomcat, LockOutRealm mishandled case sensitivity in usernames, resulting in less effective blocking of brute force attacks.",
          "title": "Vulnerability description"
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        {
          "category": "summary",
          "text": "tomcat-catalina: Apache Tomcat: Improper Handling of Case Sensitivity in LockOutRealm",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "A flaw was found in Apache Tomcat\u0027s LockOutRealm. When configured with an underlying Realm where usernames are case-insensitive, the LockOutRealm does not account for case differences, potentially reducing the effectiveness of brute-force protection. Exploitation requires LockOutRealm to be configured with a case-insensitive authentication backend, which is a non-default configuration.",
          "title": "Statement"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product\u0027s status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
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        },
        {
          "category": "external",
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        }
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      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-23T11:17:32+00:00",
          "details": "For details on how to apply this update, which includes the changes described in this advisory, refer to:\nhttps://images.redhat.com/",
          "product_ids": [
            "Red Hat Hardened Images:tomcat11-main@noarch",
            "Red Hat Hardened Images:tomcat11-main@src"
          ],
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            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:44427"
        },
        {
          "category": "workaround",
          "details": "This vulnerability only affects Tomcat deployments using the LockOutRealm with a case-insensitive authentication backend. Deployments not using LockOutRealm or using case-sensitive authentication backends are not affected.",
          "product_ids": [
            "Red Hat Hardened Images:tomcat11-main@noarch",
            "Red Hat Hardened Images:tomcat11-main@src"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:tomcat11-main@noarch",
            "Red Hat Hardened Images:tomcat11-main@src"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "tomcat-catalina: Apache Tomcat: Improper Handling of Case Sensitivity in LockOutRealm"
    }
  ]
}

CVE-2026-43513 (GCVE-0-2026-43513)

Vulnerability from cvelistv5 – Published: 2026-05-12 15:26 – Updated: 2026-05-14 19:53

Title

Apache Tomcat: LockOutRealm treats user names as case-sensitive

Summary

Improper Handling of Case Sensitivity vulnerability in LockOutRealm 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 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Older unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-14 16:34 UTC

CWE

CWE-178 - Improper Handling of Case Sensitivity

Assigner

apache

References

2 references

URL	Tags
https://lists.apache.org/thread/ytjcgldshj73lcnd1…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/05/12/9

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache Tomcat	Affected: 11.0.0-M1 , ≤ 11.0.21 (semver) Affected: 10.1.0-M1 , ≤ 10.1.54 (semver) Affected: 9.0.0.M1 , ≤ 9.0.117 (semver) Affected: 8.5.0 , ≤ 8.5.100 (semver) Affected: 7.0.0 , ≤ 7.0.109 (semver) Unknown: 0 , < 7.00 (semver)

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

RHSA-2026:44427

CVE-2026-43513 (GCVE-0-2026-43513)

Tags

Sightings

Nomenclature