Vulnerability-Lookup

GHSA-3847-FGF2-64XP

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them

Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers. This patch also disables BH when transmitting the skb to address a possible migration to different CPU leading to imbalanced decrementation of the recursion counters.

This is modeled after Florian Westphal's dev_xmit_recursion*() API available since commit 97cdcf37b57e ("net: place xmit recursion in softnet data") according to its current state in the tree.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74260"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:25Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them\n\nUpdate nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.\nThis patch also disables BH when transmitting the skb to address a\npossible migration to different CPU leading to imbalanced decrementation\nof the recursion counters.\n\nThis is modeled after Florian Westphal\u0027s dev_xmit_recursion*() API\navailable since commit 97cdcf37b57e (\"net: place xmit recursion in\nsoftnet data\") according to its current state in the tree.",
  "id": "GHSA-3847-fgf2-64xp",
  "modified": "2026-08-17T06:33:34Z",
  "published": "2026-08-15T06:32:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74260"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2354e975932dabb06fad239f07a3b68fd1809737"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/edf234f71fb327792196f813048ab8f5bd3bb712"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74260 (GCVE-0-2026-74260)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:57 – Updated: 2026-08-17 05:45

Title

netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them Update nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers. This patch also disables BH when transmitting the skb to address a possible migration to different CPU leading to imbalanced decrementation of the recursion counters. This is modeled after Florian Westphal's dev_xmit_recursion*() API available since commit 97cdcf37b57e ("net: place xmit recursion in softnet data") according to its current state in the tree.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/edf234f71fb327792…
https://git.kernel.org/stable/c/2354e975932dabb06…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f37ad91270397a6d053e8623bdb3cf79859691d2 , < edf234f71fb327792196f813048ab8f5bd3bb712 (git) Affected: f37ad91270397a6d053e8623bdb3cf79859691d2 , < 2354e975932dabb06fad239f07a3b68fd1809737 (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_dup_netdev.h",
            "net/netfilter/nf_dup_netdev.c",
            "net/netfilter/nft_fwd_netdev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "edf234f71fb327792196f813048ab8f5bd3bb712",
              "status": "affected",
              "version": "f37ad91270397a6d053e8623bdb3cf79859691d2",
              "versionType": "git"
            },
            {
              "lessThan": "2354e975932dabb06fad239f07a3b68fd1809737",
              "status": "affected",
              "version": "f37ad91270397a6d053e8623bdb3cf79859691d2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_dup_netdev.h",
            "net/netfilter/nf_dup_netdev.c",
            "net/netfilter/nft_fwd_netdev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them\n\nUpdate nft_dup and nft_fwd to use the nf_dev_xmit_recursion() helpers.\nThis patch also disables BH when transmitting the skb to address a\npossible migration to different CPU leading to imbalanced decrementation\nof the recursion counters.\n\nThis is modeled after Florian Westphal\u0027s dev_xmit_recursion*() API\navailable since commit 97cdcf37b57e (\"net: place xmit recursion in\nsoftnet data\") according to its current state in the tree."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The flaw is reached through nftables netdev fwd/dup evaluation on NF_NETDEV ingress/egress hooks installed via nfnetlink; kernel CNA guidance treats netfilter/nftables configuration and packet-hook paths as Local even when traffic ultimately arrives from the network.\nAC:L - An attacker with CAP_NET_ADMIN can deterministically install netdev egress/ingress fwd or dup rules that loop (same device or mutual forwarding) and drive packets through them; concurrent traffic also lets the attacker influence CPU migration that desynchronizes the per-CPU recursion counter without uncontrollable races.\nPR:L - Installing netdev nftables fwd/dup rules requires CAP_NET_ADMIN via nfnetlink (netlink_net_capable), but that capability is routinely obtainable in an unprivileged-created user+network namespace (unshare -Urn) and is commonly delegated to containers with NET_ADMIN.\nUI:N - Exploitation needs only the attacker\u0027s own nftables/netlink setup and packet injection; no victim must mount filesystems, open files, click prompts, or perform any deliberate interactive action beyond ordinary traffic delivery.\nS:U - Impact is unbounded kernel-stack recursion and crash/panic within the same kernel security domain; it does not cross a VM, container, IOMMU, or other distinct security-authority boundary such as guest-to-host escape.\nC:H - Bypassing the nf_dup_skb_recursion limit allows unbounded nf_hook_egress/ingress re-entry that corrupts kernel stack frames before the guard page; such stack corruption can disclose adjacent kernel memory and is not a pure NULL-deref crash with no data exposure.\nI:H - Unbounded recursion overflows the kernel task stack and overwrites saved return addresses/control data on the stack, providing a standard path to arbitrary kernel writes and control-flow hijack rather than a bounded or crash-only integrity effect.\nA:H - When the per-CPU recursion counter is desynchronized by CPU migration without local_bh_disable(), fwd/dup netdev rules can recurse without bound through neigh_xmit/dev_queue_xmit and nf_hook_egress, exhausting the kernel stack and causing oops/panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:45:09.808Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/edf234f71fb327792196f813048ab8f5bd3bb712"
        },
        {
          "url": "https://git.kernel.org/stable/c/2354e975932dabb06fad239f07a3b68fd1809737"
        }
      ],
      "title": "netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74260",
    "datePublished": "2026-08-15T05:57:37.579Z",
    "dateReserved": "2026-08-15T05:44:03.877Z",
    "dateUpdated": "2026-08-17T05:45:09.808Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-3847-FGF2-64XP

CVE-2026-74260 (GCVE-0-2026-74260)

Tags

Sightings

Nomenclature