CVE-2026-99083 affecting package kernel 6.6.157.1-1

{
  "id": "8ebc58449366e61803690722da8d4f49421b69f70eec89dc7f7775b852808e98",
  "url": "https://osv.dev/vulnerability/AZL-110990",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-99083 affecting package kernel 6.6.157.1-1",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds write in krb5_authenticate() In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-first element of a compounded SMB2 request, the calculation omits work->next_smb2_rsp_hdr_off. This causes out_len to overstate remaining buffer headroom by the cumulative size of prior responses in the compound chain. Consequently, the length check in ksmbd_krb5_authenticate() (*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy() to write the AP-REP blob past the end of response_buf into adjacent kernel heap memory. Fix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len, ensuring it accurately reflects physical remaining buffer space.",
    "evidence": "osv:AZL-110990",
    "products": [
      {
        "name": {
          "value": "kernel",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "AZL-110990",
      "aliases": [
        "AZL-110990"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "6.6.157.1-1"
                }
              ]
            }
          ],
          "package": {
            "name": "kernel",
            "purl": "pkg:rpm/azure-linux/kernel",
            "ecosystem": "Azure Linux:3"
          },
          "database_specific": {
            "source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-110990.json"
          }
        }
      ],
      "modified": "2026-10-27T05:36:16Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-99083"
      ],
      "references": [
        "https://nvd.nist.gov/vuln/detail/CVE-2026-99083"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-99083",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 460660,
  "published_at": "2026-10-23T13:17:32+00:00"
}