Vulnerability-Lookup

GHSA-8P4M-4F3F-9XQP

Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-19 18:32

Details

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

net/iucv: fix use-after-free of a severed iucv_path

af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() -- a use-after-free of the freed iucv_path.

Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued.

Severity

8.8 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-68140"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T13:19:59Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/iucv: fix use-after-free of a severed iucv_path\n\naf_iucv queues not-yet-received message notifications on iucv-\u003emessage_q,\neach holding a raw pointer to the connection\u0027s iucv_path.  When the peer\nsevers the connection, iucv_sever_path() frees that path with\niucv_path_free() but leaves the notifications queued.  A later recvmsg()\ndrains message_q via iucv_process_message_q() and hands the stale path to\nmessage_receive() -- a use-after-free of the freed iucv_path.\n\nDrop the queued notifications when the path is severed; once the path is\ngone they can no longer be received.  This also frees the notifications\nleaked when a socket is closed with messages still queued.",
  "id": "GHSA-8p4m-4f3f-9xqp",
  "modified": "2026-08-19T18:32:06Z",
  "published": "2026-08-10T15:33:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68140"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/23658b350b4107e8292045c2044983fd426fa15d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5f08c5e50bcb4680069bd3f9edd5728308816ded"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/900cd6d8119b7f3ae5c4bf82f922ff5957df43db"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/99ddb33748698296a6f17b9b34aa3d16a406bb3c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5bbaddf69853117f28173c3f5c8fc14c6b2ec82"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c24faf11bd31bfe0500aca12cbdd5a573a954a5d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f579582c03ed526281a8450159baf1d35099a85f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-68140 (GCVE-0-2026-68140)

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-19 16:29

Title

net/iucv: fix use-after-free of a severed iucv_path

Summary

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use-after-free of a severed iucv_path af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() -- a use-after-free of the freed iucv_path. Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued.

Severity

8.8 (High)


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

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/5f08c5e50bcb46800…
https://git.kernel.org/stable/c/c24faf11bd31bfe05…
https://git.kernel.org/stable/c/99ddb33748698296a…
https://git.kernel.org/stable/c/23658b350b4107e82…
https://git.kernel.org/stable/c/a5bbaddf69853117f…
https://git.kernel.org/stable/c/900cd6d8119b7f3ae…
https://git.kernel.org/stable/c/f579582c03ed52628…
https://git.kernel.org/stable/c/be7cc4656eb1f5402…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f0703c80e5156406ad947cb67fe277725b48080f , < 5f08c5e50bcb4680069bd3f9edd5728308816ded (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < c24faf11bd31bfe0500aca12cbdd5a573a954a5d (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < 99ddb33748698296a6f17b9b34aa3d16a406bb3c (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < 23658b350b4107e8292045c2044983fd426fa15d (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < a5bbaddf69853117f28173c3f5c8fc14c6b2ec82 (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < 900cd6d8119b7f3ae5c4bf82f922ff5957df43db (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < f579582c03ed526281a8450159baf1d35099a85f (git) Affected: f0703c80e5156406ad947cb67fe277725b48080f , < be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a (git)
Linux	Linux	Affected: 2.6.24 Unaffected: 0 , < 2.6.24 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.148 , ≤ 6.6.* (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 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": [
            "net/iucv/af_iucv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5f08c5e50bcb4680069bd3f9edd5728308816ded",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "c24faf11bd31bfe0500aca12cbdd5a573a954a5d",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "99ddb33748698296a6f17b9b34aa3d16a406bb3c",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "23658b350b4107e8292045c2044983fd426fa15d",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "a5bbaddf69853117f28173c3f5c8fc14c6b2ec82",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "900cd6d8119b7f3ae5c4bf82f922ff5957df43db",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "f579582c03ed526281a8450159baf1d35099a85f",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            },
            {
              "lessThan": "be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a",
              "status": "affected",
              "version": "f0703c80e5156406ad947cb67fe277725b48080f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/iucv/af_iucv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.24"
            },
            {
              "lessThan": "2.6.24",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "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": "5.10.265",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.216",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.183",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.148",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.24",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/iucv: fix use-after-free of a severed iucv_path\n\naf_iucv queues not-yet-received message notifications on iucv-\u003emessage_q,\neach holding a raw pointer to the connection\u0027s iucv_path.  When the peer\nsevers the connection, iucv_sever_path() frees that path with\niucv_path_free() but leaves the notifications queued.  A later recvmsg()\ndrains message_q via iucv_process_message_q() and hands the stale path to\nmessage_receive() -- a use-after-free of the freed iucv_path.\n\nDrop the queued notifications when the path is severed; once the path is\ngone they can no longer be received.  This also frees the notifications\nleaked when a socket is closed with messages still queued."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - An adjacent z/VM guest or LPAR peer can establish an AF_IUCV connection and deliver IUCV message_pending and path_severed events to a victim; exploitation requires same-CPC IUCV reachability, not Internet-wide access.\nAC:L - The attacker deterministically floods IUCV messages to fill message_q, severs the connection to free iucv_path, then victim recvmsg() drains the stale queue; no uncontrollable timing or memory-layout luck is required.\nPR:N - On the victim, no local Linux account or capability is needed; any unauthorized adjacent IUCV peer that completes the AF_IUCV handshake can flood messages and sever the path against a listening service.\nUI:N - No special victim action is required beyond normal server recvmsg() on an established IUCV session; the attacker drives connection setup, message flood, and path sever entirely from the peer side.\nS:U - Impact is kernel memory corruption within the victim Linux guest; it does not cross hypervisor, VM-escape, or IOMMU security boundaries.\nC:H - Queued notifications dereference a freed struct iucv_path in message_receive(), passing stale pathid and private fields into CP IUCV RECEIVE calls\u2014a classic UAF enabling attacker-controlled heap reuse and kernel memory disclosure.\nI:H - Use-after-free of iucv_path lets an attacker reclaim the freed object and supply forged pathid and list pointers used by __iucv_message_receive(), providing heap corruption primitives suitable for arbitrary kernel write or code execution.\nA:H - Processing the stale path in iucv_process_message_q() dereferences freed kernel memory during message_receive(), reliably causing kernel oops or panic and total loss of availability even before full exploitation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-19T16:29:57.127Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5f08c5e50bcb4680069bd3f9edd5728308816ded"
        },
        {
          "url": "https://git.kernel.org/stable/c/c24faf11bd31bfe0500aca12cbdd5a573a954a5d"
        },
        {
          "url": "https://git.kernel.org/stable/c/99ddb33748698296a6f17b9b34aa3d16a406bb3c"
        },
        {
          "url": "https://git.kernel.org/stable/c/23658b350b4107e8292045c2044983fd426fa15d"
        },
        {
          "url": "https://git.kernel.org/stable/c/a5bbaddf69853117f28173c3f5c8fc14c6b2ec82"
        },
        {
          "url": "https://git.kernel.org/stable/c/900cd6d8119b7f3ae5c4bf82f922ff5957df43db"
        },
        {
          "url": "https://git.kernel.org/stable/c/f579582c03ed526281a8450159baf1d35099a85f"
        },
        {
          "url": "https://git.kernel.org/stable/c/be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a"
        }
      ],
      "title": "net/iucv: fix use-after-free of a severed iucv_path",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68140",
    "datePublished": "2026-08-10T11:59:03.761Z",
    "dateReserved": "2026-07-30T09:28:09.370Z",
    "dateUpdated": "2026-08-19T16:29:57.127Z",
    "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-8P4M-4F3F-9XQP

CVE-2026-68140 (GCVE-0-2026-68140)

Tags

Sightings

Nomenclature