{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "6b7f3cf96364eaf597940cb5c68a682894829915"
            },
            {
              "fixed": "76b94cbd32aacf36a641956385a852635c6802b9"
            },
            {
              "fixed": "c8e4e0c701d0192a2efb6df059c0f9e19678c23d"
            },
            {
              "fixed": "6c344fff2feff9d4d716d8e4ad40e9b5040ee5ea"
            },
            {
              "fixed": "427ab81a811dab4bca9d19f82eec5847ae42646e"
            },
            {
              "fixed": "012d37a568bfbb2c9686f03ade75560bc7139956"
            },
            {
              "fixed": "30aae62e50b4e074a90a9a5e15246548fbdc1182"
            },
            {
              "fixed": "41fe0f7b84f0cb822ae10ab08592996a592b2a25"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "5.15.211"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.177"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.144"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.95"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.38"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53391.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr\n\nnfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a\nnetaddr4 from a GETDEVICEINFO multipath-DS body, then immediately\ncalls strrchr(buf, '.') to locate the port separator. Both decodes\nuse xdr_stream_decode_string_dup(), and the current code checks only\n\"nlen \u003c 0\" / \"rlen \u003c 0\" before dereferencing the returned string.\n\nWhen the on-wire opaque has length zero, xdr_stream_decode_opaque_inline()\nreturns 0 and xdr_stream_decode_string_dup() falls through to its\n\"*str = NULL; return ret\" tail, leaving buf NULL with a return value\nof 0. The \"\u003c 0\" check does not catch this, and the next line is\nstrrchr(NULL, '.'), a kernel NULL pointer dereference reachable from\nany pNFS-flexfile client mounted against a malicious or compromised\nmetadata server.\n\nReject the zero-length cases explicitly so the decoder fails with\n-EBADMSG (treated as a malformed GETDEVICEINFO body) instead of\npanicking the client.",
  "id": "CVE-2026-53391",
  "modified": "2026-07-22T05:30:00.344653553Z",
  "published": "2026-07-19T12:01:55.521Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/012d37a568bfbb2c9686f03ade75560bc7139956"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/30aae62e50b4e074a90a9a5e15246548fbdc1182"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/41fe0f7b84f0cb822ae10ab08592996a592b2a25"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/427ab81a811dab4bca9d19f82eec5847ae42646e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6c344fff2feff9d4d716d8e4ad40e9b5040ee5ea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/76b94cbd32aacf36a641956385a852635c6802b9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c8e4e0c701d0192a2efb6df059c0f9e19678c23d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53391.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53391"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr"
}