{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:apache:httpclient:5.6:-:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "5.6-NA"
              },
              {
                "last_affected": "5.6-NA"
              }
            ],
            "source": "CPE_STRING"
          },
          "events": [
            {
              "introduced": "decd193d2b615fa18146a9f8392f201d736faf4b"
            },
            {
              "last_affected": "decd193d2b615fa18146a9f8392f201d736faf4b"
            }
          ],
          "repo": "https://github.com/apache/httpcomponents-client",
          "type": "GIT"
        }
      ],
      "versions": [
        "5.6-NA"
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "apache",
    "cwe_ids": [
      "CWE-304"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40542.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "5.6"
          },
          {
            "fixed": "5.6.1"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version 5.6.1, which fixes this issue.",
  "id": "CVE-2026-40542",
  "modified": "2026-07-16T03:30:49.968644297Z",
  "published": "2026-04-22T07:07:21.344Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/04/22/5"
    },
    {
      "type": "WEB",
      "url": "https://repo.maven.apache.org/maven2"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40542.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-40542"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40542.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40542"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460518"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Apache HttpClient: SCRAM-SHA-256 mutual authentication bypass may cause the client to accept authentication without proper mutual authentication verification"
}