{
  "document": {
    "aggregate_severity": {
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      "text": "Moderate"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Copyright \u00a9 Red Hat, Inc. All rights reserved.",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "summary",
        "text": "An update for Red Hat Hardened Images RPMs is now available.",
        "title": "Topic"
      },
      {
        "category": "general",
        "text": "This update includes the following RPMs:\n\nlibidn2:\n  * idn2-2.3.8-4.hum1 (aarch64, x86_64)\n  * libidn2-2.3.8-4.hum1 (aarch64, x86_64)\n  * libidn2-devel-2.3.8-4.hum1 (aarch64, x86_64)\n  * libidn2-2.3.8-4.hum1.src (src)",
        "title": "Details"
      },
      {
        "category": "legal_disclaimer",
        "text": "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.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://access.redhat.com/security/team/contact/",
      "issuing_authority": "Red Hat Product Security is responsible for vulnerability handling across all Red Hat products and services.",
      "name": "Red Hat Product Security",
      "namespace": "https://www.redhat.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "https://access.redhat.com/errata/RHSA-2026:42125",
        "url": "https://access.redhat.com/errata/RHSA-2026:42125"
      },
      {
        "category": "external",
        "summary": "https://images.redhat.com/",
        "url": "https://images.redhat.com/"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/cve/CVE-2026-57053",
        "url": "https://access.redhat.com/security/cve/CVE-2026-57053"
      },
      {
        "category": "external",
        "summary": "https://access.redhat.com/security/updates/classification/",
        "url": "https://access.redhat.com/security/updates/classification/"
      },
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_42125.json"
      }
    ],
    "title": "Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update",
    "tracking": {
      "current_release_date": "2026-09-07T22:44:16+00:00",
      "generator": {
        "date": "2026-09-07T22:44:16+00:00",
        "engine": {
          "name": "Red Hat SDEngine",
          "version": "5.3.16"
        }
      },
      "id": "RHSA-2026:42125",
      "initial_release_date": "2026-07-20T17:30:07+00:00",
      "revision_history": [
        {
          "date": "2026-07-20T17:30:07+00:00",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-09-04T00:36:24+00:00",
          "number": "2",
          "summary": "Last updated version"
        },
        {
          "date": "2026-09-07T22:44:16+00:00",
          "number": "3",
          "summary": "Last generated version"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Red Hat Hardened Images",
                "product": {
                  "name": "Red Hat Hardened Images",
                  "product_id": "Red Hat Hardened Images",
                  "product_identification_helper": {
                    "cpe": "cpe:/a:redhat:hummingbird:1"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Red Hat Hardened Images"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "libidn2-main@aarch64",
                "product": {
                  "name": "libidn2-main@aarch64",
                  "product_id": "libidn2-main@aarch64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/idn2@2.3.8-4.hum1?arch=aarch64\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-aarch64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "aarch64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "libidn2-main@x86_64",
                "product": {
                  "name": "libidn2-main@x86_64",
                  "product_id": "libidn2-main@x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/idn2@2.3.8-4.hum1?arch=x86_64\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-x86_64-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "libidn2-main@src",
                "product": {
                  "name": "libidn2-main@src",
                  "product_id": "libidn2-main@src",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/redhat/libidn2@2.3.8-4.hum1?arch=src\u0026distro=hummingbird-20251124\u0026repository_id=public-hummingbird-source-rpms"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "src"
          }
        ],
        "category": "vendor",
        "name": "Red Hat"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "libidn2-main@aarch64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:libidn2-main@aarch64"
        },
        "product_reference": "libidn2-main@aarch64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "libidn2-main@src as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:libidn2-main@src"
        },
        "product_reference": "libidn2-main@src",
        "relates_to_product_reference": "Red Hat Hardened Images"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "libidn2-main@x86_64 as a component of Red Hat Hardened Images",
          "product_id": "Red Hat Hardened Images:libidn2-main@x86_64"
        },
        "product_reference": "libidn2-main@x86_64",
        "relates_to_product_reference": "Red Hat Hardened Images"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-57053",
      "cwe": {
        "id": "CWE-125",
        "name": "Out-of-bounds Read"
      },
      "discovery_date": "2026-06-23T18:02:12.362861+00:00",
      "ids": [
        {
          "system_name": "Red Hat Bugzilla ID",
          "text": "2491878"
        }
      ],
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in GNU libidn. This vulnerability allows an attacker to cause out-of-bounds reads of uninitialized memory within the ToUnicode APIs due to mishandling in the `idna_to_unicode_internal` function. This could lead to information disclosure or a denial of service.",
          "title": "Vulnerability description"
        },
        {
          "category": "summary",
          "text": "libidn: GNU libidn: Out-of-bounds read in ToUnicode APIs",
          "title": "Vulnerability summary"
        },
        {
          "category": "other",
          "text": "This flaw resides in GNU libidn\u0027s idna_to_unicode_internal() function, used by the idna_to_unicode_* API family. The function assumes its internal ToASCII comparison buffer always begins with the \"xn--\" ACE prefix. When a decoded label is pure ASCII and shorter than four characters, no prefix is added, and the round-trip verification instead reads past the buffer\u0027s null terminator into uninitialized stack memory. Under certain call sequences that leave matching residual data on the stack, this allows an ACE-encoded label that should fail validation to be silently accepted and normalized to a different, shorter string, which could affect domain-based security decisions (allow/deny-list matching, hostname comparisons, routing, logging) made by applications relying on the result.\n\nThis flaw does not affect libidn2. Its round-trip verification in lookup.c never assumes the \"xn--\" prefix is present on caller-supplied data; every prefix-relative offset is either guarded by an explicit prefix check beforehand or applied to a buffer the function itself just wrote the prefix into, and it compares the full label rather than a bare suffix.",
          "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": {
        "fixed": [
          "Red Hat Hardened Images:libidn2-main@aarch64",
          "Red Hat Hardened Images:libidn2-main@src",
          "Red Hat Hardened Images:libidn2-main@x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://access.redhat.com/security/cve/CVE-2026-57053"
        },
        {
          "category": "external",
          "summary": "RHBZ#2491878",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2491878"
        },
        {
          "category": "external",
          "summary": "https://www.cve.org/CVERecord?id=CVE-2026-57053",
          "url": "https://www.cve.org/CVERecord?id=CVE-2026-57053"
        },
        {
          "category": "external",
          "summary": "https://nvd.nist.gov/vuln/detail/CVE-2026-57053",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-57053"
        },
        {
          "category": "external",
          "summary": "https://lists.gnu.org/archive/html/help-libidn/2026-05/msg00000.html",
          "url": "https://lists.gnu.org/archive/html/help-libidn/2026-05/msg00000.html"
        },
        {
          "category": "external",
          "summary": "https://lists.gnu.org/archive/html/help-libidn/2026-06/msg00001.html",
          "url": "https://lists.gnu.org/archive/html/help-libidn/2026-06/msg00001.html"
        }
      ],
      "release_date": "2026-06-23T16:40:22.947000+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-20T17:30:07+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:libidn2-main@aarch64",
            "Red Hat Hardened Images:libidn2-main@src",
            "Red Hat Hardened Images:libidn2-main@x86_64"
          ],
          "restart_required": {
            "category": "none"
          },
          "url": "https://access.redhat.com/errata/RHSA-2026:42125"
        },
        {
          "category": "workaround",
          "details": "No configuration-level mitigation is available; triggering the incorrect result depends on uninitialized stack content from earlier processing, so behavior is non-deterministic and cannot be reliably suppressed via input filtering. Users should update to a fixed libidn package once available. Applications that must process untrusted internationalized domain names before a fix is available should treat output of idna_to_unicode_8z8z()/idna_to_unicode_8zlz() as unverified, perform an independent comparison against the original ACE-encoded input, or use libidn2 for IDNA processing, which is not affected.",
          "product_ids": [
            "Red Hat Hardened Images:libidn2-main@aarch64",
            "Red Hat Hardened Images:libidn2-main@src",
            "Red Hat Hardened Images:libidn2-main@x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 2.9,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "Red Hat Hardened Images:libidn2-main@aarch64",
            "Red Hat Hardened Images:libidn2-main@src",
            "Red Hat Hardened Images:libidn2-main@x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ],
      "title": "libidn: GNU libidn: Out-of-bounds read in ToUnicode APIs"
    }
  ]
}