Vulnerability-Lookup

GHSA-Q643-38MV-P69J

Vulnerability from github – Published: 2026-10-23 15:31 – Updated: 2026-10-23 15:31

Details

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

vsock/virtio: account only unread bytes in read_skb()

After a partial stream receive, rx_bytes tracks the unread suffix while buf_used and peer credit still cover the whole packet. virtio_transport_read_skb() dequeues that packet but passes pkt_len for both counters, underflowing rx_bytes.

On a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read from a 100-byte packet made SIOCINQ report -40, an empty recv return ELOOP, and poll report the empty socket readable. After verdict detach, receiving 40 bytes wrapped the counter to zero and hid those queued bytes until one more byte arrived. The fixed run kept the counter balanced and exposed all queued data immediately.

This was found during an LLM-assisted manual source audit of VSOCK receive accounting while re-evaluating virtio_transport_read_skb() after CVE-2024-50169.

Subtract only skb->len minus the VSOCK offset from rx_bytes. Retain the full packet length for buf_used and peer credit.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-99062"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-23T13:17:30Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: account only unread bytes in read_skb()\n\nAfter a partial stream receive, rx_bytes tracks the unread suffix while\nbuf_used and peer credit still cover the whole packet.\nvirtio_transport_read_skb() dequeues that packet but passes pkt_len for\nboth counters, underflowing rx_bytes.\n\nOn a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read\nfrom a 100-byte packet made SIOCINQ report -40, an empty recv return\nELOOP, and poll report the empty socket readable.  After verdict detach,\nreceiving 40 bytes wrapped the counter to zero and hid those queued bytes\nuntil one more byte arrived.  The fixed run kept the counter balanced\nand exposed all queued data immediately.\n\nThis was found during an LLM-assisted manual source audit of VSOCK\nreceive accounting while re-evaluating virtio_transport_read_skb() after\nCVE-2024-50169.\n\nSubtract only skb-\u003elen minus the VSOCK offset from rx_bytes.  Retain the\nfull packet length for buf_used and peer credit.",
  "id": "GHSA-q643-38mv-p69j",
  "modified": "2026-10-23T15:31:37Z",
  "published": "2026-10-23T15:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99062"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/38bad3930b1185dd6c98db3dd342ddc123c6f3ef"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a463f55c791b96cfd12df8b10ea737d45c80bb18"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dd4b2f88ee517f9629d0d3dbfced02ffbc33e2dc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e4a0028b0d54b2c45e1dc8c0dd95fe3e9236f55b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-99062 (GCVE-0-2026-99062)

Vulnerability from cvelistv5 – Published: 2026-10-23 12:23 – Updated: 2026-10-23 12:23

Title

vsock/virtio: account only unread bytes in read_skb()

Summary

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: account only unread bytes in read_skb() After a partial stream receive, rx_bytes tracks the unread suffix while buf_used and peer credit still cover the whole packet. virtio_transport_read_skb() dequeues that packet but passes pkt_len for both counters, underflowing rx_bytes. On a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read from a 100-byte packet made SIOCINQ report -40, an empty recv return ELOOP, and poll report the empty socket readable. After verdict detach, receiving 40 bytes wrapped the counter to zero and hid those queued bytes until one more byte arrived. The fixed run kept the counter balanced and exposed all queued data immediately. This was found during an LLM-assisted manual source audit of VSOCK receive accounting while re-evaluating virtio_transport_read_skb() after CVE-2024-50169. Subtract only skb->len minus the VSOCK offset from rx_bytes. Retain the full packet length for buf_used and peer credit.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7067 records in the last 180 days details

References

4 references

URL	Tags
https://git.kernel.org/stable/c/e4a0028b0d54b2c45…
https://git.kernel.org/stable/c/38bad3930b1185dd6…
https://git.kernel.org/stable/c/dd4b2f88ee517f962…
https://git.kernel.org/stable/c/a463f55c791b96cfd…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7893a41deaf28b53036d4ea7cd9f7d54e8874dfc , < e4a0028b0d54b2c45e1dc8c0dd95fe3e9236f55b (git) Affected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 , < 38bad3930b1185dd6c98db3dd342ddc123c6f3ef (git) Affected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 , < dd4b2f88ee517f9629d0d3dbfced02ffbc33e2dc (git) Affected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 , < a463f55c791b96cfd12df8b10ea737d45c80bb18 (git) Affected: 17bada47e9ac3621c28e0ffa89af8279fedea00a (git) Affected: 6.12.34 , < 6.12.113 (semver) Affected: 6.15.3 , < 6.16 (semver)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.12.113 , ≤ 6.12.* (semver) Unaffected: 6.18.57 , ≤ 6.18.* (semver) Unaffected: 7.2.11 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/virtio_transport_common.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e4a0028b0d54b2c45e1dc8c0dd95fe3e9236f55b",
              "status": "affected",
              "version": "7893a41deaf28b53036d4ea7cd9f7d54e8874dfc",
              "versionType": "git"
            },
            {
              "lessThan": "38bad3930b1185dd6c98db3dd342ddc123c6f3ef",
              "status": "affected",
              "version": "45ca7e9f0730ae36fc610e675b990e9cc9ca0714",
              "versionType": "git"
            },
            {
              "lessThan": "dd4b2f88ee517f9629d0d3dbfced02ffbc33e2dc",
              "status": "affected",
              "version": "45ca7e9f0730ae36fc610e675b990e9cc9ca0714",
              "versionType": "git"
            },
            {
              "lessThan": "a463f55c791b96cfd12df8b10ea737d45c80bb18",
              "status": "affected",
              "version": "45ca7e9f0730ae36fc610e675b990e9cc9ca0714",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "17bada47e9ac3621c28e0ffa89af8279fedea00a",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.113",
              "status": "affected",
              "version": "6.12.34",
              "versionType": "semver"
            },
            {
              "lessThan": "6.16",
              "status": "affected",
              "version": "6.15.3",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/virtio_transport_common.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": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "6.12.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.11",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.15.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: account only unread bytes in read_skb()\n\nAfter a partial stream receive, rx_bytes tracks the unread suffix while\nbuf_used and peer credit still cover the whole packet.\nvirtio_transport_read_skb() dequeues that packet but passes pkt_len for\nboth counters, underflowing rx_bytes.\n\nOn a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read\nfrom a 100-byte packet made SIOCINQ report -40, an empty recv return\nELOOP, and poll report the empty socket readable.  After verdict detach,\nreceiving 40 bytes wrapped the counter to zero and hid those queued bytes\nuntil one more byte arrived.  The fixed run kept the counter balanced\nand exposed all queued data immediately.\n\nThis was found during an LLM-assisted manual source audit of VSOCK\nreceive accounting while re-evaluating virtio_transport_read_skb() after\nCVE-2024-50169.\n\nSubtract only skb-\u003elen minus the VSOCK offset from rx_bytes.  Retain the\nfull packet length for buf_used and peer credit."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-23T12:23:03.360Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e4a0028b0d54b2c45e1dc8c0dd95fe3e9236f55b"
        },
        {
          "url": "https://git.kernel.org/stable/c/38bad3930b1185dd6c98db3dd342ddc123c6f3ef"
        },
        {
          "url": "https://git.kernel.org/stable/c/dd4b2f88ee517f9629d0d3dbfced02ffbc33e2dc"
        },
        {
          "url": "https://git.kernel.org/stable/c/a463f55c791b96cfd12df8b10ea737d45c80bb18"
        }
      ],
      "title": "vsock/virtio: account only unread bytes in read_skb()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99062",
    "datePublished": "2026-10-23T12:23:03.360Z",
    "dateReserved": "2026-09-25T10:25:14.388Z",
    "dateUpdated": "2026-10-23T12:23:03.360Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted