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

Vulnerability from cvelistv5 – Published: 2026-05-12 15:26 – Updated: 2026-05-14 19:53
VLAI?
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 ?
No CVSS data available.
CWE
  • CWE-178 - Improper Handling of Case Sensitivity
Assigner
References
Impacted products
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)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-05-12T17:41:00.529Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/05/12/9"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-43513",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-14T16:34:43.121351Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-14T19:53:30.781Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Apache Tomcat",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThanOrEqual": "11.0.21",
              "status": "affected",
              "version": "11.0.0-M1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "10.1.54",
              "status": "affected",
              "version": "10.1.0-M1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "9.0.117",
              "status": "affected",
              "version": "9.0.0.M1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "8.5.100",
              "status": "affected",
              "version": "8.5.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.109",
              "status": "affected",
              "version": "7.0.0",
              "versionType": "semver"
            },
            {
              "lessThan": "7.00",
              "status": "unknown",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eImproper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat.\u003c/p\u003e\u003cp\u003eThis 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.\u003cbr\u003eOlder unsupported versions may also be affected.\u003c/p\u003e\u003cp\u003eUsers are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.\u003c/p\u003e"
            }
          ],
          "value": "Improper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat.\n\nThis 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.\nOlder unsupported versions may also be affected.\n\nUsers are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "text": "low"
            },
            "type": "Textual description of severity"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-178",
              "description": "CWE-178 Improper Handling of Case Sensitivity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-12T15:26:25.599Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Apache Tomcat: LockOutRealm treats user names as case-sensitive",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2026-43513",
    "datePublished": "2026-05-12T15:26:25.599Z",
    "dateReserved": "2026-05-01T16:21:04.703Z",
    "dateUpdated": "2026-05-14T19:53:30.781Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-43513",
      "date": "2026-05-17",
      "epss": "0.00062",
      "percentile": "0.19321"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-43513\",\"sourceIdentifier\":\"security@apache.org\",\"published\":\"2026-05-12T16:16:18.177\",\"lastModified\":\"2026-05-15T15:53:14.517\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Improper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat.\\n\\nThis 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.\\nOlder unsupported versions may also be affected.\\n\\nUsers are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security@apache.org\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-178\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"7.0.0\",\"versionEndIncluding\":\"7.0.109\",\"matchCriteriaId\":\"5BE0EC99-5BCD-4F7F-8124-4A1734B7BF6B\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"8.5.0\",\"versionEndIncluding\":\"8.5.100\",\"matchCriteriaId\":\"FF43D0D7-FBF3-4D7A-84C4-47B65A75A524\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"9.0.0\",\"versionEndExcluding\":\"9.0.118\",\"matchCriteriaId\":\"1E5A897C-91F4-449E-984C-7D693B137EED\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"10.1.0\",\"versionEndExcluding\":\"10.1.55\",\"matchCriteriaId\":\"5F289287-8587-4BB3-B4AB-3B5CF4A7D27A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"11.0.0\",\"versionEndExcluding\":\"11.0.22\",\"matchCriteriaId\":\"03FB799D-A66F-4792-A0CF-16D67BB53F08\"}]}]}],\"references\":[{\"url\":\"https://lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp\",\"source\":\"security@apache.org\",\"tags\":[\"Mailing List\",\"Vendor Advisory\"]},{\"url\":\"http://www.openwall.com/lists/oss-security/2026/05/12/9\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"http://www.openwall.com/lists/oss-security/2026/05/12/9\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2026-05-12T17:41:00.529Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-43513\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-14T16:34:43.121351Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-14T16:34:55.590Z\"}}], \"cna\": {\"title\": \"Apache Tomcat: LockOutRealm treats user names as case-sensitive\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"metrics\": [{\"other\": {\"type\": \"Textual description of severity\", \"content\": {\"text\": \"low\"}}}], \"affected\": [{\"vendor\": \"Apache Software Foundation\", \"product\": \"Apache Tomcat\", \"versions\": [{\"status\": \"affected\", \"version\": \"11.0.0-M1\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"11.0.21\"}, {\"status\": \"affected\", \"version\": \"10.1.0-M1\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"10.1.54\"}, {\"status\": \"affected\", \"version\": \"9.0.0.M1\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"9.0.117\"}, {\"status\": \"affected\", \"version\": \"8.5.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"8.5.100\"}, {\"status\": \"affected\", \"version\": \"7.0.0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"7.0.109\"}, {\"status\": \"unknown\", \"version\": \"0\", \"lessThan\": \"7.00\", \"versionType\": \"semver\"}], \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp\", \"tags\": [\"vendor-advisory\"]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Improper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat.\\n\\nThis 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.\\nOlder unsupported versions may also be affected.\\n\\nUsers are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eImproper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat.\u003c/p\u003e\u003cp\u003eThis 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.\u003cbr\u003eOlder unsupported versions may also be affected.\u003c/p\u003e\u003cp\u003eUsers are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-178\", \"description\": \"CWE-178 Improper Handling of Case Sensitivity\"}]}], \"providerMetadata\": {\"orgId\": \"f0158376-9dc2-43b6-827c-5f631a4d8d09\", \"shortName\": \"apache\", \"dateUpdated\": \"2026-05-12T15:26:25.599Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-43513\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-14T19:53:30.781Z\", \"dateReserved\": \"2026-05-01T16:21:04.703Z\", \"assignerOrgId\": \"f0158376-9dc2-43b6-827c-5f631a4d8d09\", \"datePublished\": \"2026-05-12T15:26:25.599Z\", \"assignerShortName\": \"apache\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.