Vulnerability-Lookup

GHSA-JC3M-QG79-3244

Vulnerability from github – Published: 2026-03-25 12:30 – Updated: 2026-03-25 12:30

Details

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().

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-23331"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-25T11:16:30Z",
    "severity": null
  },
  "details": "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().",
  "id": "GHSA-jc3m-qg79-3244",
  "modified": "2026-03-25T12:30:23Z",
  "published": "2026-03-25T12:30:23Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23331"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b8f104880c104151f8c30f2f89df81fb59a286c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b955350778b8715e1b7885179979b3a68221c0fb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23331 (GCVE-0-2026-23331)

Vulnerability from cvelistv5 – Published: 2026-03-25 10:27 – Updated: 2026-03-25 10:27

Title

udp: Unhash auto-bound connected sk from 4-tuple hash table when disconnected.

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().

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/b955350778b8715e1…
	https://git.kernel.org/stable/c/3b8f104880c104151…
	https://git.kernel.org/stable/c/6996a2d2d0a64808c…

Impacted products

Vendor

Product

Version

Linux

Affected: 78c91ae2c6deb5d236a5a93ff2995cdd05514380 , < b955350778b8715e1b7885179979b3a68221c0fb (git)
Affected: 78c91ae2c6deb5d236a5a93ff2995cdd05514380 , < 3b8f104880c104151f8c30f2f89df81fb59a286c (git)
Affected: 78c91ae2c6deb5d236a5a93ff2995cdd05514380 , < 6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4 (git)

Linux

Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.18.17 , ≤ 6.18.* (semver)
Unaffected: 6.19.7 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.17",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.7",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0-rc3",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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()."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-25T10:27:22.526Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b955350778b8715e1b7885179979b3a68221c0fb"
        },
        {
          "url": "https://git.kernel.org/stable/c/3b8f104880c104151f8c30f2f89df81fb59a286c"
        },
        {
          "url": "https://git.kernel.org/stable/c/6996a2d2d0a64808c19c98002aeb5d9d1b2df6a4"
        }
      ],
      "title": "udp: Unhash auto-bound connected sk from 4-tuple hash table when disconnected.",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23331",
    "datePublished": "2026-03-25T10:27:22.526Z",
    "dateReserved": "2026-01-13T15:37:45.996Z",
    "dateUpdated": "2026-03-25T10:27:22.526Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-JC3M-QG79-3244

CVE-2026-23331 (GCVE-0-2026-23331)

Tags

Sightings

Nomenclature