CVE-2026-68140 (GCVE-0-2026-68140)
Vulnerability from cvelistv5
Published
2026-08-10 11:59
Modified
2026-08-19 16:29
Severity ?
VLAI Severity ?
EPSS score ?
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.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f Version: f0703c80e5156406ad947cb67fe277725b48080f |
||
{
"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": [
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"programFiles": [
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],
"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": [
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"vulnerable": true
},
{
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}
],
"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"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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