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CVE-2026-98491

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry In a case where skb with an unconfirmed ct entry gets cloned, we may end up committing both but with different sets of extensions. The series of events: 1. The first clone wants to commit and runs the helpers wiring up the extension pointer into the expectation list. 2. Then it looses the confirmation keeping the entry unconfirmed. 3. Second clone now wants to commit labels and adds the new extension for that breaking the pointer in the expectation list causing UAF on the destruction path later. While this is possible to trigger, there should be no practical network pipeline where committing both clones without modifications into the same zone is needed. So, let's just reset the entry in case for some reason we got an skb with a shared one during commit. This doesn't affect any known use cases, but avoids any potential problems with sharing and modification of the unconfirmed ct entry. The fixes tag points to the introduction of helpers, since that's the main UAF trigger for the sharing.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-18 16:17:00.020000
Last modified
2026-10-24 14:16:44.297000
View original CVE JSON 
{
  "id": "CVE-2026-98491",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:00.020",
  "lastModified": "2026-10-24T14:16:44.297",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: conntrack: avoid modifying shared unconfirmed ct entry\n\nIn a case where skb with an unconfirmed ct entry gets cloned, we may\nend up committing both but with different sets of extensions.\n\nThe series of events:\n\n 1. The first clone wants to commit and runs the helpers wiring up\n    the extension pointer into the expectation list.\n 2. Then it looses the confirmation keeping the entry unconfirmed.\n 3. Second clone now wants to commit labels and adds the new extension\n    for that breaking the pointer in the expectation list causing\n    UAF on the destruction path later.\n\nWhile this is possible to trigger, there should be no practical\nnetwork pipeline where committing both clones without modifications\ninto the same zone is needed.  So, let's just reset the entry in case\nfor some reason we got an skb with a shared one during commit.  This\ndoesn't affect any known use cases, but avoids any potential problems\nwith sharing and modification of the unconfirmed ct entry.\n\nThe fixes tag points to the introduction of helpers, since that's the\nmain UAF trigger for the sharing."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "include/net/netfilter/nf_conntrack.h",
            "net/openvswitch/conntrack.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "e0fa5ea434b7e8467ef3adc64e3858b1ca2a642d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "37e3c878b183a115f9a114067f9ef3b408ad27fb",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "707c2dc77891a874f4e8c52c285a511079164ec8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "de41ee24f77b0fc45397db3e277cae2adbd43dfe",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "55e5256adf3940e71802e2f749cacf81518726b0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "e2829ae5459ddb5fce526b2e84697edf6c0c3cef",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "457e0df1b5711fbeb7ba1b6bfd826f5ef30e7e55",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "cae3a2627520c3795b54533c5328b77af3405dbe",
              "lessThan": "26b2bd70d22457556e2fa01cbf1192cb1a94d619",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "include/net/netfilter/nf_conntrack.h",
            "net/openvswitch/conntrack.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.3",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.3",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.55",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "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
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/26b2bd70d22457556e2fa01cbf1192cb1a94d619",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/37e3c878b183a115f9a114067f9ef3b408ad27fb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/457e0df1b5711fbeb7ba1b6bfd826f5ef30e7e55",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/55e5256adf3940e71802e2f749cacf81518726b0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/707c2dc77891a874f4e8c52c285a511079164ec8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/de41ee24f77b0fc45397db3e277cae2adbd43dfe",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e0fa5ea434b7e8467ef3adc64e3858b1ca2a642d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e2829ae5459ddb5fce526b2e84697edf6c0c3cef",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}