{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: ah: account for ESN high bits in async callbacks\n\nAH allocates its temporary auth/ICV layout differently when ESN is enabled:\nthe async ahash setup appends a 4-byte seqhi slot before the ICV or\nauth_data area, but the async completion callbacks still reconstruct the\ntemporary layout as if seqhi were absent.\n\nWith an async AH implementation selected, that makes AH copy or compare\nthe wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH\nwith ESN and forced async hmac(sha1), ping fails with 100% packet loss,\nand the callback logs show the pre-fix drift:\n\n  ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24\n  ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36\n\nReconstruct the callback-side layout the same way the setup path built it\nby skipping the ESN seqhi slot before locating the saved auth_data or ICV.\nPer RFC 4302, the ESN high-order 32 bits participate in the AH ICV\ncomputation, so the async callbacks must account for the seqhi slot.\n\nPost-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows\nthe corrected offset (ah4 output_done: esn=1 err=0 icv_off=24\nexpected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o\nbuild clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the\nchange has not been tested against a real async hardware AH engine."
    }
  ],
  "id": "CVE-2026-46193",
  "lastModified": "2026-05-28T13:44:01.663",
  "metrics": {},
  "published": "2026-05-28T10:16:34.923",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0555d4f526232b3c9e3afbcd490c0c0793aefec6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2ffaa7a94f9a4d22724364a1821735a0231d9f8d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/729899a2aa8bda7844be0cdcd3b470f11b912eda"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7db99a09b3bc87268287bc7ab5f2e7f382b5ad87"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ec54093e6a8f87e800bb6aa15eb7fc1e33faa524"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-46193"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-28T10:16:34Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: ah: account for ESN high bits in async callbacks\n\nAH allocates its temporary auth/ICV layout differently when ESN is enabled:\nthe async ahash setup appends a 4-byte seqhi slot before the ICV or\nauth_data area, but the async completion callbacks still reconstruct the\ntemporary layout as if seqhi were absent.\n\nWith an async AH implementation selected, that makes AH copy or compare\nthe wrong bytes on both the IPv4 and IPv6 paths. In UML repro on IPv4 AH\nwith ESN and forced async hmac(sha1), ping fails with 100% packet loss,\nand the callback logs show the pre-fix drift:\n\n  ah4 output_done: esn=1 err=0 icv_off=20 expected_off=24\n  ah4 input_done: esn=1 auth_off=20 expected_auth_off=24 icv_off=32 expected_icv_off=36\n\nReconstruct the callback-side layout the same way the setup path built it\nby skipping the ESN seqhi slot before locating the saved auth_data or ICV.\nPer RFC 4302, the ESN high-order 32 bits participate in the AH ICV\ncomputation, so the async callbacks must account for the seqhi slot.\n\nPost-fix, the same IPv4 AH+ESN+forced-async-hmac(sha1) UML repro shows\nthe corrected offset (ah4 output_done: esn=1 err=0 icv_off=24\nexpected_off=24) and ping succeeds; net/ipv4/ah4.o and net/ipv6/ah6.o\nbuild clean at W=1. IPv6 AH+ESN was not exercised at runtime, and the\nchange has not been tested against a real async hardware AH engine.",
  "id": "GHSA-h5pr-w979-v38m",
  "modified": "2026-05-28T12:30:32Z",
  "published": "2026-05-28T12:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46193"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0555d4f526232b3c9e3afbcd490c0c0793aefec6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2ffaa7a94f9a4d22724364a1821735a0231d9f8d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/729899a2aa8bda7844be0cdcd3b470f11b912eda"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7db99a09b3bc87268287bc7ab5f2e7f382b5ad87"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec54093e6a8f87e800bb6aa15eb7fc1e33faa524"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-46193 xfrm: ah: account for ESN high bits in async callbacks - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-46193.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "xfrm: ah: account for ESN high bits in async callbacks",
    "tracking": {
      "current_release_date": "2026-05-29T01:09:30.000Z",
      "generator": {
        "date": "2026-05-29T07:23:45.840Z",
        "engine": {
          "name": "MSRC Generator",
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        }
      },
      "id": "msrc_CVE-2026-46193",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-29T01:09:30.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-46193",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "under_investigation": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-46193 xfrm: ah: account for ESN high bits in async callbacks - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-46193.json"
        }
      ],
      "title": "xfrm: ah: account for ESN high bits in async callbacks"
    }
  ]
}