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CVE-2026-72405

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync Yue Sun reported a use-after-free and debugobjects warning in udp_tunnel_nic_device_sync_work() during concurrent device operations. The workqueue core clears the internal pending bit before invoking the worker. At that point, a concurrent thread can queue the work again. When the already running worker eventually clears the work_pending flag to 0, it mistakenly clears the flag for the newly queued instance. udp_tunnel_nic_unregister() then observes work_pending as 0 and frees the structure while the second work item is still active in the queue, leading to UAF. Fix this by returning early in udp_tunnel_nic_device_sync() if work_pending is already set, preventing redundant work queueing.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-15 06:22:14.077000
Last modified
2026-10-30 13:19:51.400000
View original CVE JSON 
{
  "id": "CVE-2026-72405",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-15T06:22:14.077",
  "lastModified": "2026-10-30T13:19:51.400",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_sync\n\nYue Sun reported a use-after-free and debugobjects warning in\nudp_tunnel_nic_device_sync_work() during concurrent device operations.\n\nThe workqueue core clears the internal pending bit before invoking the\nworker. At that point, a concurrent thread can queue the work again.\nWhen the already running worker eventually clears the work_pending flag\nto 0, it mistakenly clears the flag for the newly queued instance.\nudp_tunnel_nic_unregister() then observes work_pending as 0 and frees\nthe structure while the second work item is still active in the queue,\nleading to UAF.\n\nFix this by returning early in udp_tunnel_nic_device_sync() if\nwork_pending is already set, preventing redundant work queueing."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/ipv4/udp_tunnel_nic.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "d59d3b19e1cd1a01a6db59705327387a30aed153",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "cee6688e5731c0591643521716d1a1a5c1a98bf8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "54292b167466cdf42176b7b6f01da66c184deb12",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
              "lessThan": "ecf69d4b43370c587e48d4d70289dbdb7e039d4d",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/ipv4/udp_tunnel_nic.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.9",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.9",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.97",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.40",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.5",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T18:49:07.638343Z",
          "id": "CVE-2026-72405",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/54292b167466cdf42176b7b6f01da66c184deb12",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9075efb9b2c1d9d7a8285c937b64aa93ca0c41b7",
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    },
    {
      "url": "https://git.kernel.org/stable/c/cee6688e5731c0591643521716d1a1a5c1a98bf8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d59d3b19e1cd1a01a6db59705327387a30aed153",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ecf69d4b43370c587e48d4d70289dbdb7e039d4d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f49ed02fd8c98da823fdd7b00d64a8cc1d1883ac",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  ]
}