Vulnerability-Lookup

FKIE_CVE-2026-74476

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-17 06:19

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: veth: convert frag_list skbs before running XDP A frag_list skb can reach veth with data_len set but nr_frags zero. veth_convert_skb_to_xdp_buff() only converts skbs that are shared, locked, have frags[], or do not have enough headroom. It later uses skb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and xdp_frags_size. That exposes frag_list data to XDP as if it were stored in frags[], but frags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment metadata, walk an empty fragment entry, and crash in memcpy() from __xsk_rcv(). Route non-linear skbs through skb_pp_cow_data() before exposing them to XDP, and only advertise XDP frags when the resulting skb has frags[]. skb_copy_bits() already handles frag_list input, and skb_pp_cow_data() builds frags[] output with skb_add_rx_frag(), which is the representation XDP multi-buffer expects.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/5c1c15c540fc45820ce3033c319151ec891bc10a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d0d6415963040c401e7a7e4e482a698ba52448cb
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f9c1fff857e93be709c8b52ed1a643f37bd82c66

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/veth.c",
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5c1c15c540fc45820ce3033c319151ec891bc10a",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "f9c1fff857e93be709c8b52ed1a643f37bd82c66",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "d0d6415963040c401e7a7e4e482a698ba52448cb",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/veth.c",
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: convert frag_list skbs before running XDP\n\nA frag_list skb can reach veth with data_len set but nr_frags zero.\nveth_convert_skb_to_xdp_buff() only converts skbs that are shared,\nlocked, have frags[], or do not have enough headroom. It later uses\nskb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and\nxdp_frags_size.\n\nThat exposes frag_list data to XDP as if it were stored in frags[], but\nfrags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment\nmetadata, walk an empty fragment entry, and crash in memcpy() from\n__xsk_rcv().\n\nRoute non-linear skbs through skb_pp_cow_data() before exposing them to\nXDP, and only advertise XDP frags when the resulting skb has frags[].\nskb_copy_bits() already handles frag_list input, and skb_pp_cow_data()\nbuilds frags[] output with skb_add_rx_frag(), which is the\nrepresentation XDP multi-buffer expects."
    }
  ],
  "id": "CVE-2026-74476",
  "lastModified": "2026-08-17T06:19:43.663",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T13:17:52.397",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c1c15c540fc45820ce3033c319151ec891bc10a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0d6415963040c401e7a7e4e482a698ba52448cb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f9c1fff857e93be709c8b52ed1a643f37bd82c66"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-74476 (GCVE-0-2026-74476)

Vulnerability from cvelistv5 – Published: 2026-08-15 12:27 – Updated: 2026-08-17 05:47

Title

veth: convert frag_list skbs before running XDP

Summary

Severity

9.1 (Critical)


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

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/5c1c15c540fc45820…
https://git.kernel.org/stable/c/b24ba0bbffe3e23eb…
https://git.kernel.org/stable/c/f9c1fff857e93be70…
https://git.kernel.org/stable/c/d0d6415963040c401…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 718a18a0c8a67f97781e40bdef7cdd055c430996 , < 5c1c15c540fc45820ce3033c319151ec891bc10a (git) Affected: 718a18a0c8a67f97781e40bdef7cdd055c430996 , < b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb (git) Affected: 718a18a0c8a67f97781e40bdef7cdd055c430996 , < f9c1fff857e93be709c8b52ed1a643f37bd82c66 (git) Affected: 718a18a0c8a67f97781e40bdef7cdd055c430996 , < d0d6415963040c401e7a7e4e482a698ba52448cb (git)
Linux	Linux	Affected: 5.18 Unaffected: 0 , < 5.18 (semver) Unaffected: 6.12.103 , ≤ 6.12.* (semver) Unaffected: 6.18.44 , ≤ 6.18.* (semver) Unaffected: 7.1.8 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/veth.c",
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5c1c15c540fc45820ce3033c319151ec891bc10a",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "f9c1fff857e93be709c8b52ed1a643f37bd82c66",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            },
            {
              "lessThan": "d0d6415963040c401e7a7e4e482a698ba52448cb",
              "status": "affected",
              "version": "718a18a0c8a67f97781e40bdef7cdd055c430996",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/veth.c",
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "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": "6.12.103",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: convert frag_list skbs before running XDP\n\nA frag_list skb can reach veth with data_len set but nr_frags zero.\nveth_convert_skb_to_xdp_buff() only converts skbs that are shared,\nlocked, have frags[], or do not have enough headroom. It later uses\nskb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and\nxdp_frags_size.\n\nThat exposes frag_list data to XDP as if it were stored in frags[], but\nfrags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment\nmetadata, walk an empty fragment entry, and crash in memcpy() from\n__xsk_rcv().\n\nRoute non-linear skbs through skb_pp_cow_data() before exposing them to\nXDP, and only advertise XDP frags when the resulting skb has frags[].\nskb_copy_bits() already handles frag_list input, and skb_pp_cow_data()\nbuilds frags[] output with skb_add_rx_frag(), which is the\nrepresentation XDP multi-buffer expects."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is hit when a received skb traverses veth XDP processing; in cloud/container deployments (e.g. Cloudflare-style edge nodes) remote traffic routed to a veth peer with XDP+AF_XDP can deliver the malformed frag_list skb without local access.\nAC:L - An attacker can reliably supply the required frag_list skb (data_len\u003e0, nr_frags=0) by transmitting from the veth peer via sockets or GRO aggregation, controlling packet size, timing, and content without depending on uncontrollable kernel state.\nPR:N - Remote exploitation needs no attacker privileges when ingress traffic reaches a veth that already has an XDP program redirecting to an AF_XDP socket; only network-delivered skbs trigger veth_convert_skb_to_xdp_buff() and the faulty __xsk_rcv() path.\nUI:N - No victim user action is required beyond normal network traffic reaching the veth interface; exploitation is automatic once a qualifying frag_list skb is received and redirected to AF_XDP copy mode.\nS:U - The flaw causes kernel memory reads and crashes within the host kernel security boundary; it does not cross VM, hypervisor, or IOMMU isolation boundaries.\nC:H - Bogus XDP_FLAGS_HAS_FRAGS metadata makes __xsk_rcv() memcpy from uninitialized frags[] entries via skb_frag_address(), enabling out-of-bounds kernel memory reads into the AF_XDP receive buffer before faulting.\nI:N - The failure mode is a kernel-side memcpy read using invalid fragment metadata; data is copied into the attacker\u0027s AF_XDP ring buffer rather than corrupting kernel or other tenants\u0027 memory for integrity purposes.\nA:H - The commit and code path confirm a kernel crash when __xsk_rcv() follows bogus fragment metadata and memcpy faults on an invalid frags[] source address, causing oops/panic and denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:47:37.441Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5c1c15c540fc45820ce3033c319151ec891bc10a"
        },
        {
          "url": "https://git.kernel.org/stable/c/b24ba0bbffe3e23eb2f6838881c1fabcb29fb9fb"
        },
        {
          "url": "https://git.kernel.org/stable/c/f9c1fff857e93be709c8b52ed1a643f37bd82c66"
        },
        {
          "url": "https://git.kernel.org/stable/c/d0d6415963040c401e7a7e4e482a698ba52448cb"
        }
      ],
      "title": "veth: convert frag_list skbs before running XDP",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74476",
    "datePublished": "2026-08-15T12:27:11.309Z",
    "dateReserved": "2026-08-15T05:44:03.903Z",
    "dateUpdated": "2026-08-17T05:47:37.441Z",
    "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

FKIE_CVE-2026-74476

CVE-2026-74476 (GCVE-0-2026-74476)

Tags

Sightings

Nomenclature