Vulnerability-Lookup

GHSA-62JP-JVC3-7HH9

Vulnerability from github – Published: 2026-03-18 18:31 – Updated: 2026-03-18 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks

As Paolo said earlier [1]:

"Since the blamed commit below, classify can return TC_ACT_CONSUMED while the current skb being held by the defragmentation engine. As reported by GangMin Kim, if such packet is that may cause a UaF when the defrag engine later on tries to tuch again such packet."

act_ct was never meant to be used in the egress path, however some users are attaching it to egress today [2]. Attempting to reach a middle ground, we noticed that, while most qdiscs are not handling TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we address the issue by only allowing act_ct to bind to clsact/ingress qdiscs and shared blocks. That way it's still possible to attach act_ct to egress (albeit only with clsact).

[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ [2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23270"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-18T18:16:26Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks\n\nAs Paolo said earlier [1]:\n\n\"Since the blamed commit below, classify can return TC_ACT_CONSUMED while\nthe current skb being held by the defragmentation engine. As reported by\nGangMin Kim, if such packet is that may cause a UaF when the defrag engine\nlater on tries to tuch again such packet.\"\n\nact_ct was never meant to be used in the egress path, however some users\nare attaching it to egress today [2]. Attempting to reach a middle\nground, we noticed that, while most qdiscs are not handling\nTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we\naddress the issue by only allowing act_ct to bind to clsact/ingress\nqdiscs and shared blocks. That way it\u0027s still possible to attach act_ct to\negress (albeit only with clsact).\n\n[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/\n[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/",
  "id": "GHSA-62jp-jvc3-7hh9",
  "modified": "2026-03-18T18:31:18Z",
  "published": "2026-03-18T18:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23270"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/11cb63b0d1a0685e0831ae3c77223e002ef18189"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/524ce8b4ea8f64900b6c52b6a28df74f6bc0801e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9deda0fcda5c1f388c5e279541850b71a2ccfcf4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23270 (GCVE-0-2026-23270)

Vulnerability from cvelistv5 – Published: 2026-03-18 17:54 – Updated: 2026-03-18 17:54

Title

net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks

Summary

In the Linux kernel, the following vulnerability has been resolved: net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks As Paolo said earlier [1]: "Since the blamed commit below, classify can return TC_ACT_CONSUMED while the current skb being held by the defragmentation engine. As reported by GangMin Kim, if such packet is that may cause a UaF when the defrag engine later on tries to tuch again such packet." act_ct was never meant to be used in the egress path, however some users are attaching it to egress today [2]. Attempting to reach a middle ground, we noticed that, while most qdiscs are not handling TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we address the issue by only allowing act_ct to bind to clsact/ingress qdiscs and shared blocks. That way it's still possible to attach act_ct to egress (albeit only with clsact). [1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ [2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/524ce8b4ea8f64900…
	https://git.kernel.org/stable/c/380ad8b7c65ea7aa1…
	https://git.kernel.org/stable/c/9deda0fcda5c1f388…
	https://git.kernel.org/stable/c/11cb63b0d1a0685e0…

Impacted products

Vendor

Product

Version

Linux

Affected: 3f14b377d01d8357eba032b4cabc8c1149b458b6 , < 524ce8b4ea8f64900b6c52b6a28df74f6bc0801e (git)
Affected: 3f14b377d01d8357eba032b4cabc8c1149b458b6 , < 380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6 (git)
Affected: 3f14b377d01d8357eba032b4cabc8c1149b458b6 , < 9deda0fcda5c1f388c5e279541850b71a2ccfcf4 (git)
Affected: 3f14b377d01d8357eba032b4cabc8c1149b458b6 , < 11cb63b0d1a0685e0831ae3c77223e002ef18189 (git)
Affected: 172ba7d46c202e679f3ccb10264c67416aaeb1c4 (git)
Affected: 0b5b831122fc3789fff75be433ba3e4dd7b779d4 (git)
Affected: 73f7da5fd124f2cda9161e2e46114915e6e82e97 (git)
Affected: f5346df0591d10bc948761ca854b1fae6d2ef441 (git)

Linux

Affected: 6.8
Unaffected: 0 , < 6.8 (semver)
Unaffected: 6.12.77 , ≤ 6.12.* (semver)
Unaffected: 6.18.18 , ≤ 6.18.* (semver)
Unaffected: 6.19.8 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/act_api.h",
            "net/sched/act_ct.c",
            "net/sched/cls_api.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "524ce8b4ea8f64900b6c52b6a28df74f6bc0801e",
              "status": "affected",
              "version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
              "versionType": "git"
            },
            {
              "lessThan": "380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6",
              "status": "affected",
              "version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
              "versionType": "git"
            },
            {
              "lessThan": "9deda0fcda5c1f388c5e279541850b71a2ccfcf4",
              "status": "affected",
              "version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
              "versionType": "git"
            },
            {
              "lessThan": "11cb63b0d1a0685e0831ae3c77223e002ef18189",
              "status": "affected",
              "version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "172ba7d46c202e679f3ccb10264c67416aaeb1c4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0b5b831122fc3789fff75be433ba3e4dd7b779d4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "73f7da5fd124f2cda9161e2e46114915e6e82e97",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f5346df0591d10bc948761ca854b1fae6d2ef441",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/act_api.h",
            "net/sched/act_ct.c",
            "net/sched/cls_api.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.8"
            },
            {
              "lessThan": "6.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.77",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.18",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.8",
              "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": "6.12.77",
                  "versionStartIncluding": "6.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.18",
                  "versionStartIncluding": "6.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.8",
                  "versionStartIncluding": "6.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0-rc3",
                  "versionStartIncluding": "6.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.148",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.1.75",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.7.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks\n\nAs Paolo said earlier [1]:\n\n\"Since the blamed commit below, classify can return TC_ACT_CONSUMED while\nthe current skb being held by the defragmentation engine. As reported by\nGangMin Kim, if such packet is that may cause a UaF when the defrag engine\nlater on tries to tuch again such packet.\"\n\nact_ct was never meant to be used in the egress path, however some users\nare attaching it to egress today [2]. Attempting to reach a middle\nground, we noticed that, while most qdiscs are not handling\nTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we\naddress the issue by only allowing act_ct to bind to clsact/ingress\nqdiscs and shared blocks. That way it\u0027s still possible to attach act_ct to\negress (albeit only with clsact).\n\n[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/\n[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-18T17:54:43.803Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/524ce8b4ea8f64900b6c52b6a28df74f6bc0801e"
        },
        {
          "url": "https://git.kernel.org/stable/c/380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6"
        },
        {
          "url": "https://git.kernel.org/stable/c/9deda0fcda5c1f388c5e279541850b71a2ccfcf4"
        },
        {
          "url": "https://git.kernel.org/stable/c/11cb63b0d1a0685e0831ae3c77223e002ef18189"
        }
      ],
      "title": "net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23270",
    "datePublished": "2026-03-18T17:54:43.803Z",
    "dateReserved": "2026-01-13T15:37:45.991Z",
    "dateUpdated": "2026-03-18T17:54:43.803Z",
    "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-62JP-JVC3-7HH9

CVE-2026-23270 (GCVE-0-2026-23270)

Tags

Sightings

Nomenclature