Apache Tomcat: LockOutRealm treats user names as case-sensitive

{
  "id": "5e28f779fe414672da94ea51853361578c5cdd3de7b0213cc1b2d24ef73e9716",
  "url": "https://osv.dev/vulnerability/CVE-2026-43513",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "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.",
    "evidence": "osv:CVE-2026-43513",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-43513",
      "aliases": [
        "BIT-tomcat-2026-43513",
        "CVE-2026-43513",
        "GHSA-5mp6-jrq3-r938"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/apache/tomcat",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e498667bd7811e846771a852b16ce9f1e524b81b"
                },
                {
                  "last_affected": "2cdef2c0241cdf70b5edd88d3733a52e6b675047"
                },
                {
                  "introduced": "e37b977db6f47e4380ad67114a49e8568951c953"
                },
                {
                  "last_affected": "eddcf278ad919382608ada1898b2c5b63675c6d5"
                },
                {
                  "introduced": "16bf392c67833ad549733b58c350ff92b5ee782a"
                },
                {
                  "fixed": "b4aab5184c1cf1acc0e845e0fd7306dee578e16b"
                },
                {
                  "introduced": "e9d17cddc285615807ec5fef09240777436b25dc"
                },
                {
                  "fixed": "c70966726754f8b3ab63b5ac846a7e7cf6eb255a"
                },
                {
                  "introduced": "56e547d387ab49f688c93fe9ca082b1b5d94deed"
                },
                {
                  "fixed": "ccdf7a8c736bde0f4875a10667b21cddbd4be21f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "7.0.0"
                      },
                      {
                        "last_affected": "7.0.109"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "8.5.0"
                      },
                      {
                        "last_affected": "8.5.100"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "9.0.0"
                      },
                      {
                        "fixed": "9.0.118"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "10.1.0"
                      },
                      {
                        "fixed": "10.1.55"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "11.0.0"
                      },
                      {
                        "fixed": "11.0.22"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43513.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:39.451620760Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43513.json",
        "https://lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-43513"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-178"
        ],
        "cna_assigner": "apache",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "11.0.0-M1"
                  },
                  {
                    "last_affected": "11.0.21"
                  },
                  {
                    "introduced": "10.1.0-M1"
                  },
                  {
                    "last_affected": "10.1.54"
                  },
                  {
                    "introduced": "9.0.0.M1"
                  },
                  {
                    "last_affected": "9.0.117"
                  },
                  {
                    "introduced": "8.5.0"
                  },
                  {
                    "last_affected": "8.5.100"
                  },
                  {
                    "introduced": "7.0.0"
                  },
                  {
                    "last_affected": "7.0.109"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43513.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-43513",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507202,
  "published_at": "2026-05-12T15:26:25.599+00:00"
}