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

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-19 16:29
VLAI
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
References
Impacted products
Vendor Product Version CPE status
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)
guessed Create a notification for this product.
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)
guessed Create a notification for this product.
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          "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."
        }
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            "version": "3.1"
          },
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              "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."
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        "dateUpdated": "2026-08-19T16:29:57.127Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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    "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"
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This also frees the notifications\\nleaked when a socket is closed with messages still queued.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/iucv/af_iucv.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"5f08c5e50bcb4680069bd3f9edd5728308816ded\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"c24faf11bd31bfe0500aca12cbdd5a573a954a5d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"99ddb33748698296a6f17b9b34aa3d16a406bb3c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"23658b350b4107e8292045c2044983fd426fa15d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"a5bbaddf69853117f28173c3f5c8fc14c6b2ec82\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"900cd6d8119b7f3ae5c4bf82f922ff5957df43db\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"f579582c03ed526281a8450159baf1d35099a85f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f0703c80e5156406ad947cb67fe277725b48080f\",\"lessThan\":\"be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/iucv/af_iucv.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.24\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.24\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.265\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.216\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"ADJACENT_NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/23658b350b4107e8292045c2044983fd426fa15d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5f08c5e50bcb4680069bd3f9edd5728308816ded\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/900cd6d8119b7f3ae5c4bf82f922ff5957df43db\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/99ddb33748698296a6f17b9b34aa3d16a406bb3c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a5bbaddf69853117f28173c3f5c8fc14c6b2ec82\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/be7cc4656eb1f54029610e82d1f0fdd3f9b5ec0a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c24faf11bd31bfe0500aca12cbdd5a573a954a5d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f579582c03ed526281a8450159baf1d35099a85f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-08-13T23:09:05+00:00",
      "cve": "CVE-2026-68140",
      "id": "CVE-2026-68140",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:known_affected": "261",
      "product_status:known_not_affected": "1",
      "product_status:under_investigation": "14",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/iucv: fix use-after-free of a severed iucv_path",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68140.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-18T16:56:15Z",
      "cve": "CVE-2026-68140",
      "id": "CVE-2026-68140",
      "initial_release_date": "2026-08-18T16:56:15Z",
      "product_status:known_affected": "296",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68140",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68140.json",
      "version": "2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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