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EUVD-2026-364715
European Vulnerability Database identifier assigned by ENISAReserved
2026-10-02 08:33
Assigner
ENISA
Alias of
a CVE record, shown under related vulnerabilities.
This identifier carries no description, severity or references of its own:
they belong to that CVE.
{
"assigner": "ENISA",
"date_reserved": "2026-10-02T08:33:42.067124+00:00",
"id": "EUVD-2026-364715"
}
CVE-2026-23458 (GCVE-0-2026-23458)
Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-09-08 08:46
VLAI
EPSS
VEX
Title
netfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()
Summary
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()
ctnetlink_dump_exp_ct() stores a conntrack pointer in cb->data for the
netlink dump callback ctnetlink_exp_ct_dump_table(), but drops the
conntrack reference immediately after netlink_dump_start(). When the
dump spans multiple rounds, the second recvmsg() triggers the dump
callback which dereferences the now-freed conntrack via nfct_help(ct),
leading to a use-after-free on ct->ext.
The bug is that the netlink_dump_control has no .start or .done
callbacks to manage the conntrack reference across dump rounds. Other
dump functions in the same file (e.g. ctnetlink_get_conntrack) properly
use .start/.done callbacks for this purpose.
Fix this by adding .start and .done callbacks that hold and release the
conntrack reference for the duration of the dump, and move the
nfct_help() call after the cb->args[0] early-return check in the dump
callback to avoid dereferencing ct->ext unnecessarily.
BUG: KASAN: slab-use-after-free in ctnetlink_exp_ct_dump_table+0x4f/0x2e0
Read of size 8 at addr ffff88810597ebf0 by task ctnetlink_poc/133
CPU: 1 UID: 0 PID: 133 Comm: ctnetlink_poc Not tainted 7.0.0-rc2+ #3 PREEMPTLAZY
Call Trace:
<TASK>
ctnetlink_exp_ct_dump_table+0x4f/0x2e0
netlink_dump+0x333/0x880
netlink_recvmsg+0x3e2/0x4b0
? aa_sk_perm+0x184/0x450
sock_recvmsg+0xde/0xf0
Allocated by task 133:
kmem_cache_alloc_noprof+0x134/0x440
__nf_conntrack_alloc+0xa8/0x2b0
ctnetlink_create_conntrack+0xa1/0x900
ctnetlink_new_conntrack+0x3cf/0x7d0
nfnetlink_rcv_msg+0x48e/0x510
netlink_rcv_skb+0xc9/0x1f0
nfnetlink_rcv+0xdb/0x220
netlink_unicast+0x3ec/0x590
netlink_sendmsg+0x397/0x690
__sys_sendmsg+0xf4/0x180
Freed by task 0:
slab_free_after_rcu_debug+0xad/0x1e0
rcu_core+0x5c3/0x9c0
Severity
7.8 (High)
Assigner
References
10 references
Impacted products
8 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < d8cd0efbccc5cfb0a80da744a7da76e1333ab925
(git)
Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < 9821b47f669eb82791fa0b1a6ebaf9aa219bea72 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < bdf2724eefd4455a66863abb025bab8d3aa98c57 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < f04cc86d59906513d2d62183b882966fc0ae0390 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < f025171feef2ac65663d7986f1d5ff0c28d6b2a9 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < 04c8907ce4e3d3e26c5e1a3e47aa5d17082cbb56 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < cd541f15b60e2257441398cf495d978f816d09f8 (git) Affected: e844a928431fa8f1359d1f4f2cef53d9b446bf52 , < 5cb81eeda909dbb2def209dd10636b51549a3f8a (git) |
|
| Linux | Linux |
Affected:
3.10
Unaffected: 0 , < 3.10 (semver) Unaffected: 5.10.253 , ≤ 5.10.* (semver) Unaffected: 5.15.203 , ≤ 5.15.* (semver) Unaffected: 6.1.167 , ≤ 6.1.* (semver) Unaffected: 6.6.130 , ≤ 6.6.* (semver) Unaffected: 6.12.78 , ≤ 6.12.* (semver) Unaffected: 6.18.20 , ≤ 6.18.* (semver) Unaffected: 6.19.10 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix) |
|
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
|
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.5 , < *
(custom)
|
|
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
|
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP |
Affected:
V3.1.5 , < *
(custom)
|
|
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
|
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.5 , < *
(custom)
|
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],
"providerMetadata": {
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"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"shortName": "siemens-SADP"
},
"references": [
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
}
],
"x_adpType": "supplier"
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"cna": {
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"product": "Linux",
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],
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},
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()\n\nctnetlink_dump_exp_ct() stores a conntrack pointer in cb-\u003edata for the\nnetlink dump callback ctnetlink_exp_ct_dump_table(), but drops the\nconntrack reference immediately after netlink_dump_start(). When the\ndump spans multiple rounds, the second recvmsg() triggers the dump\ncallback which dereferences the now-freed conntrack via nfct_help(ct),\nleading to a use-after-free on ct-\u003eext.\n\nThe bug is that the netlink_dump_control has no .start or .done\ncallbacks to manage the conntrack reference across dump rounds. Other\ndump functions in the same file (e.g. ctnetlink_get_conntrack) properly\nuse .start/.done callbacks for this purpose.\n\nFix this by adding .start and .done callbacks that hold and release the\nconntrack reference for the duration of the dump, and move the\nnfct_help() call after the cb-\u003eargs[0] early-return check in the dump\ncallback to avoid dereferencing ct-\u003eext unnecessarily.\n\n BUG: KASAN: slab-use-after-free in ctnetlink_exp_ct_dump_table+0x4f/0x2e0\n Read of size 8 at addr ffff88810597ebf0 by task ctnetlink_poc/133\n\n CPU: 1 UID: 0 PID: 133 Comm: ctnetlink_poc Not tainted 7.0.0-rc2+ #3 PREEMPTLAZY\n Call Trace:\n \u003cTASK\u003e\n ctnetlink_exp_ct_dump_table+0x4f/0x2e0\n netlink_dump+0x333/0x880\n netlink_recvmsg+0x3e2/0x4b0\n ? aa_sk_perm+0x184/0x450\n sock_recvmsg+0xde/0xf0\n\n Allocated by task 133:\n kmem_cache_alloc_noprof+0x134/0x440\n __nf_conntrack_alloc+0xa8/0x2b0\n ctnetlink_create_conntrack+0xa1/0x900\n ctnetlink_new_conntrack+0x3cf/0x7d0\n nfnetlink_rcv_msg+0x48e/0x510\n netlink_rcv_skb+0xc9/0x1f0\n nfnetlink_rcv+0xdb/0x220\n netlink_unicast+0x3ec/0x590\n netlink_sendmsg+0x397/0x690\n __sys_sendmsg+0xf4/0x180\n\n Freed by task 0:\n slab_free_after_rcu_debug+0xad/0x1e0\n rcu_core+0x5c3/0x9c0"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The vulnerable path is reached through a local NETLINK_NETFILTER ctnetlink request, specifically an expectation dump with CTA_EXPECT_MASTER. It is not reachable directly from unauthenticated network packets.\nAC:L - The attacker can create the relevant conntrack/expectation state, start the multipart dump, and free the master conntrack before the next recvmsg. No condition outside attacker control or difficult race is required.\nPR:L - nfnetlink requires CAP_NET_ADMIN, but the check is against the socket network namespace and is reachable by an unprivileged user via user and network namespaces. This makes the required privilege low rather than high.\nUI:N - Exploitation is driven entirely by attacker-issued netlink operations. No victim user action is required.\nS:U - The impact is within the kernel and the same local system security authority. This is a standard local kernel memory-corruption issue, not a cross-scope boundary escape such as guest-to-host.\nC:H - The bug is a use-after-free of a conntrack object and its extension pointer during a netlink dump. A freed kernel object can plausibly be reclaimed and shaped for information disclosure, so confidentiality impact is high.\nI:H - Use-after-free in kernel heap memory can plausibly be leveraged beyond a crash into memory corruption or control-flow manipulation. Following the required conservative scoring, integrity impact is high.\nA:H - The reported failure is a KASAN slab-use-after-free in kernel netlink dump handling and can cause an oops or panic. The attacker can trigger it repeatedly through local netlink requests."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T12:21:57.345Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/d8cd0efbccc5cfb0a80da744a7da76e1333ab925"
},
{
"url": "https://git.kernel.org/stable/c/9821b47f669eb82791fa0b1a6ebaf9aa219bea72"
},
{
"url": "https://git.kernel.org/stable/c/bdf2724eefd4455a66863abb025bab8d3aa98c57"
},
{
"url": "https://git.kernel.org/stable/c/f04cc86d59906513d2d62183b882966fc0ae0390"
},
{
"url": "https://git.kernel.org/stable/c/f025171feef2ac65663d7986f1d5ff0c28d6b2a9"
},
{
"url": "https://git.kernel.org/stable/c/04c8907ce4e3d3e26c5e1a3e47aa5d17082cbb56"
},
{
"url": "https://git.kernel.org/stable/c/cd541f15b60e2257441398cf495d978f816d09f8"
},
{
"url": "https://git.kernel.org/stable/c/5cb81eeda909dbb2def209dd10636b51549a3f8a"
}
],
"title": "netfilter: ctnetlink: fix use-after-free in ctnetlink_dump_exp_ct()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-23458",
"datePublished": "2026-04-03T15:15:39.041Z",
"dateReserved": "2026-01-13T15:37:46.021Z",
"dateUpdated": "2026-09-08T08:46:26.744Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Trend slope:
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(linear fit over daily sighting counts)
Show additional events:
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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
| 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.
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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.
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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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.
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