FKIE_CVE-2026-23331

Vulnerability from fkie_nvd - Published: 2026-03-25 11:16 - Updated: 2026-06-17 10:21
Severity
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: udp: Unhash auto-bound connected sk from 4-tuple hash table when disconnected. Let's say we bind() an UDP socket to the wildcard address with a non-zero port, connect() it to an address, and disconnect it from the address. bind() sets SOCK_BINDPORT_LOCK on sk->sk_userlocks (but not SOCK_BINDADDR_LOCK), and connect() calls udp_lib_hash4() to put the socket into the 4-tuple hash table. Then, __udp_disconnect() calls sk->sk_prot->rehash(sk). It computes a new hash based on the wildcard address and moves the socket to a new slot in the 4-tuple hash table, leaving a garbage in the chain that no packet hits. Let's remove such a socket from 4-tuple hash table when disconnected. Note that udp_sk(sk)->udp_portaddr_hash needs to be udpated after udp_hash4_dec(hslot2) in udp_unhash4().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3b8f104880c104151f8c30f2f89df81fb59a286cPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b955350778b8715e1b7885179979b3a68221c0fbPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 6.13
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/udp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b955350778b8715e1b7885179979b3a68221c0fb",
              "status": "affected",
              "version": "78c91ae2c6deb5d236a5a93ff2995cdd05514380",
              "versionType": "git"
            },
            {
              "lessThan": "3b8f104880c104151f8c30f2f89df81fb59a286c",
              "status": "affected",
              "version": "78c91ae2c6deb5d236a5a93ff2995cdd05514380",
              "versionType": "git"
            },
            {
              "lessThan": "6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4",
              "status": "affected",
              "version": "78c91ae2c6deb5d236a5a93ff2995cdd05514380",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/udp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "40E7536C-DA22-4B7D-9953-0343B4D9A3E6",
              "versionEndExcluding": "6.18.17",
              "versionStartIncluding": "6.13.1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3",
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              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16",
              "vulnerable": true
            },
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              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64",
              "vulnerable": true
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              "vulnerable": true
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          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nudp: Unhash auto-bound connected sk from 4-tuple hash table when disconnected.\n\nLet\u0027s say we bind() an UDP socket to the wildcard address with a\nnon-zero port, connect() it to an address, and disconnect it from\nthe address.\n\nbind() sets SOCK_BINDPORT_LOCK on sk-\u003esk_userlocks (but not\nSOCK_BINDADDR_LOCK), and connect() calls udp_lib_hash4() to put\nthe socket into the 4-tuple hash table.\n\nThen, __udp_disconnect() calls sk-\u003esk_prot-\u003erehash(sk).\n\nIt computes a new hash based on the wildcard address and moves\nthe socket to a new slot in the 4-tuple hash table, leaving a\ngarbage in the chain that no packet hits.\n\nLet\u0027s remove such a socket from 4-tuple hash table when disconnected.\n\nNote that udp_sk(sk)-\u003eudp_portaddr_hash needs to be udpated after\nudp_hash4_dec(hslot2) in udp_unhash4()."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nudp: Eliminar del hash el sk conectado auto-vinculado de la tabla hash de 4-tuplas cuando se desconecta.\n\nSupongamos que vinculamos (bind()) un socket UDP a la direcci\u00f3n comod\u00edn con un puerto no nulo, lo conectamos (connect()) a una direcci\u00f3n y lo desconectamos de la direcci\u00f3n.\n\nbind() establece SOCK_BINDPORT_LOCK en sk-\u0026gt;sk_userlocks (pero no SOCK_BINDADDR_LOCK), y connect() llama a udp_lib_hash4() para colocar el socket en la tabla hash de 4-tuplas.\n\nLuego, __udp_disconnect() llama a sk-\u0026gt;sk_prot-\u0026gt;rehash(sk).\n\nCalcula un nuevo hash basado en la direcci\u00f3n comod\u00edn y mueve el socket a una nueva ranura en la tabla hash de 4-tuplas, dejando basura en la cadena que ning\u00fan paquete alcanza.\n\nEliminemos dicho socket de la tabla hash de 4-tuplas cuando se desconecta.\n\nTenga en cuenta que udp_sk(sk)-\u0026gt;udp_portaddr_hash necesita ser actualizado despu\u00e9s de udp_hash4_dec(hslot2) en udp_unhash4()."
    }
  ],
  "id": "CVE-2026-23331",
  "lastModified": "2026-06-17T10:21:20.567",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-03-25T11:16:30.510",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/3b8f104880c104151f8c30f2f89df81fb59a286c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b955350778b8715e1b7885179979b3a68221c0fb"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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