Vulnerability-Lookup

GHSA-99X3-RPWC-XH78

Vulnerability from github – Published: 2026-10-28 12:31 – Updated: 2026-10-31 15:30

Details

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

vsock/vmci: validate packet source for connected sockets

vmci_transport_recv_stream_cb() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback can select a non-listening socket without checking whether the packet came from its stored peer.

This was reproduced with two VMCI contexts. A RST from the context not stored in a TCP_SYN_SENT socket reset that socket after it was selected by the destination-only lookup.

VMCI can process notification packets in bottom-half context when the socket is not owned by user context, or defer packets to a workqueue. Use vsock_check_source() after taking the socket lock in the bottom-half path, and recheck after lock_sock() in the workqueue path. Listening sockets continue to accept packets from any source.

Reply with a RST addressed from the received packet before dropping a source that fails validation. This preserves the existing reset behavior for bound non-listening and concurrently closed sockets without directing the reset to a connected socket's stored peer.

Severity

7.3 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-99122"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-28T11:17:31Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: validate packet source for connected sockets\n\nvmci_transport_recv_stream_cb() looks up sockets first by the full source\nand destination tuple, then by destination only in the bound table. The\nfallback can select a non-listening socket without checking whether the\npacket came from its stored peer.\n\nThis was reproduced with two VMCI contexts. A RST from the context not\nstored in a TCP_SYN_SENT socket reset that socket after it was selected by\nthe destination-only lookup.\n\nVMCI can process notification packets in bottom-half context when the\nsocket is not owned by user context, or defer packets to a workqueue. Use\nvsock_check_source() after taking the socket lock in the bottom-half path,\nand recheck after lock_sock() in the workqueue path. Listening sockets\ncontinue to accept packets from any source.\n\nReply with a RST addressed from the received packet before dropping a\nsource that fails validation. This preserves the existing reset behavior\nfor bound non-listening and concurrently closed sockets without directing\nthe reset to a connected socket\u0027s stored peer.",
  "id": "GHSA-99x3-rpwc-xh78",
  "modified": "2026-10-31T15:30:21Z",
  "published": "2026-10-28T12:31:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99122"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/90c423b62ec9be08177f74b07a47937ca8d2035b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c027f8b429dbb2157fc1b503df196e272d947c89"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-99122 (GCVE-0-2026-99122)

Vulnerability from cvelistv5 – Published: 2026-10-28 10:34 – Updated: 2026-10-31 12:43

Title

vsock/vmci: validate packet source for connected sockets

Summary

In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: validate packet source for connected sockets vmci_transport_recv_stream_cb() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback can select a non-listening socket without checking whether the packet came from its stored peer. This was reproduced with two VMCI contexts. A RST from the context not stored in a TCP_SYN_SENT socket reset that socket after it was selected by the destination-only lookup. VMCI can process notification packets in bottom-half context when the socket is not owned by user context, or defer packets to a workqueue. Use vsock_check_source() after taking the socket lock in the bottom-half path, and recheck after lock_sock() in the workqueue path. Listening sockets continue to accept packets from any source. Reply with a RST addressed from the received packet before dropping a source that fails validation. This preserves the existing reset behavior for bound non-listening and concurrently closed sockets without directing the reset to a connected socket's stored peer.

Severity

7.3 (High)


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

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/c027f8b429dbb2157…
https://git.kernel.org/stable/c/90c423b62ec9be081…
https://git.kernel.org/stable/c/ad9a7da3fa39c2d61…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: d021c344051af91f42c5ba9fdedc176740cbd238 , < c027f8b429dbb2157fc1b503df196e272d947c89 (git) Affected: d021c344051af91f42c5ba9fdedc176740cbd238 , < 90c423b62ec9be08177f74b07a47937ca8d2035b (git) Affected: d021c344051af91f42c5ba9fdedc176740cbd238 , < ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7 (git)
Linux	Linux	Affected: 3.9 Unaffected: 0 , < 3.9 (semver) Unaffected: 6.18.59 , ≤ 6.18.* (semver) Unaffected: 7.2.13 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/vmci_transport.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c027f8b429dbb2157fc1b503df196e272d947c89",
              "status": "affected",
              "version": "d021c344051af91f42c5ba9fdedc176740cbd238",
              "versionType": "git"
            },
            {
              "lessThan": "90c423b62ec9be08177f74b07a47937ca8d2035b",
              "status": "affected",
              "version": "d021c344051af91f42c5ba9fdedc176740cbd238",
              "versionType": "git"
            },
            {
              "lessThan": "ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7",
              "status": "affected",
              "version": "d021c344051af91f42c5ba9fdedc176740cbd238",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/vmw_vsock/vmci_transport.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.9"
            },
            {
              "lessThan": "3.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.59",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.13",
              "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": "6.18.59",
                  "versionStartIncluding": "3.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.13",
                  "versionStartIncluding": "3.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "3.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: validate packet source for connected sockets\n\nvmci_transport_recv_stream_cb() looks up sockets first by the full source\nand destination tuple, then by destination only in the bound table. The\nfallback can select a non-listening socket without checking whether the\npacket came from its stored peer.\n\nThis was reproduced with two VMCI contexts. A RST from the context not\nstored in a TCP_SYN_SENT socket reset that socket after it was selected by\nthe destination-only lookup.\n\nVMCI can process notification packets in bottom-half context when the\nsocket is not owned by user context, or defer packets to a workqueue. Use\nvsock_check_source() after taking the socket lock in the bottom-half path,\nand recheck after lock_sock() in the workqueue path. Listening sockets\ncontinue to accept packets from any source.\n\nReply with a RST addressed from the received packet before dropping a\nsource that fails validation. This preserves the existing reset behavior\nfor bound non-listening and concurrently closed sockets without directing\nthe reset to a connected socket\u0027s stored peer."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - A local VMCI endpoint supplies the forged control datagram through IOCTL_VMCI_DATAGRAM_SEND, reaching vmci_datagram_dispatch() and the patched vmci_transport_recv_stream_cb(); vsock is therefore Local rather than a routable network vector.\nAC:L - vsock_diag_dump() exposes socket CIDs, ports, and state without an authorization check, after which a chosen RST deterministically misses vsock_find_connected_socket() and reaches the victim through vsock_find_bound_socket(); no race or uncontrolled condition is required.\nPR:L - vmci_host_open(), IOCTL_VMCI_INIT_CONTEXT, and IOCTL_VMCI_DATAGRAM_SEND contain no capability check, allowing a low-privilege VMX/local process with ordinary VMCI-device access to create an unrestricted context and submit the packet.\nUI:N - After the victim process has an ordinary bound connecting or established socket, the attacker\u0027s datagram alone drives vmci_transport_recv_pkt_work() and the reset handler; no victim user action is required.\nS:C - A packet owned by an attacker-controlled guest/VMX VMCI context is applied to a host-context socket by vmci_transport_recv_connecting_client() or vmci_transport_recv_connected(), crossing the VMCI virtualization or VMM-sandbox boundary.\nC:L - On an established socket, a forged WAITING_READ reaches vmci_transport_handle_waiting_read(), which conditionally returns WROTE to the foreign source based on vmci_qpair_produce_buf_ready(); this exposes limited queue-occupancy and traffic-state information, not payload bytes.\nI:N - The demonstrated RST and forged notification paths do not write application payloads, alter the intended VMCI queue pair, or corrupt memory; their changes to sk_state, peer_shutdown, and notification flags implement connection disruption rather than data modification.\nA:H - vmci_transport_recv_connecting_client() sets TCP_CLOSE and ECONNRESET, while vmci_transport_recv_connected() sets SOCK_DONE, SHUTDOWN_MASK, and TCP_CLOSING. Because tuples can be re-enumerated and RST injection repeated, the attacker can continuously terminate targeted VMCI client connections and fully deny their service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-31T12:43:23.512Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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      "references": [
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          "url": "https://git.kernel.org/stable/c/c027f8b429dbb2157fc1b503df196e272d947c89"
        },
        {
          "url": "https://git.kernel.org/stable/c/90c423b62ec9be08177f74b07a47937ca8d2035b"
        },
        {
          "url": "https://git.kernel.org/stable/c/ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7"
        }
      ],
      "title": "vsock/vmci: validate packet source for connected sockets",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-99122",
    "datePublished": "2026-10-28T10:34:37.859Z",
    "dateReserved": "2026-09-25T10:25:14.393Z",
    "dateUpdated": "2026-10-31T12:43:23.512Z",
    "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

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

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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.

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