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EUVD-2026-346659
European Vulnerability Database identifier assigned by ENISAReserved
2026-10-02 08:10
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": "2026-10-02T08:10:11.088382+00:00",
"id": "EUVD-2026-346659"
}
CVE-2025-21763 (GCVE-0-2025-21763)
Vulnerability from cvelistv5 – Published: 2025-02-27 02:18 – Updated: 2026-08-05 11:54
VLAI
EPSS
VEX
Title
neighbour: use RCU protection in __neigh_notify()
Summary
In the Linux kernel, the following vulnerability has been resolved:
neighbour: use RCU protection in __neigh_notify()
__neigh_notify() can be called without RTNL or RCU protection.
Use RCU protection to avoid potential UAF.
Severity
7.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-02-27 17:57 UTC
CWE
- CWE-416 - Use After Free
Assigner
References
11 references
Impacted products
3 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
426b5303eb435d98b9bee37a807be386bc2b3320 , < e1aed6be381bcd7f46d4ca9d7ef0f5f3d6a1be32
(git)
Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < 8666e9aab801328c1408a19fbf4070609dc0695a (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < 40d8f2f2a373b6c294ffac394d2bb814b572ead1 (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < 784eb2376270e086f7db136d154b8404edacf97b (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < 1cbb2aa90cd3fba15ad7efb5cdda28f3d1082379 (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < cdd5c2a12ddad8a77ce1838ff9f29aa587de82df (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < 559307d25235e24b5424778c7332451b6c741159 (git) Affected: 426b5303eb435d98b9bee37a807be386bc2b3320 , < becbd5850c03ed33b232083dd66c6e38c0c0e569 (git) |
|
| Linux | Linux |
Affected:
2.6.25
Unaffected: 0 , < 2.6.25 (semver) Unaffected: 5.4.291 , ≤ 5.4.* (semver) Unaffected: 5.10.235 , ≤ 5.10.* (semver) Unaffected: 5.15.179 , ≤ 5.15.* (semver) Unaffected: 6.1.129 , ≤ 6.1.* (semver) Unaffected: 6.6.79 , ≤ 6.6.* (semver) Unaffected: 6.12.16 , ≤ 6.12.* (semver) Unaffected: 6.13.4 , ≤ 6.13.* (semver) Unaffected: 6.14 , ≤ * (original_commit_for_fix) |
|
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem |
Affected:
0 , < *
(custom)
|
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"providerMetadata": {
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},
{
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"title": "CVE Program Container"
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{
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"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
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"references": [
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"cna": {
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{
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"programFiles": [
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"vendor": "Linux",
"versions": [
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"versionType": "git"
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"version": "2.6.25"
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"value": "AV:L - The decisive side of the race \u2014 `dev_net_set()` during netdevice namespace migration or `default_device_exit_batch()` on netns teardown, followed by freeing the `struct net` \u2014 is driven only by local syscalls (`unshare(CLONE_NEWNET|CLONE_NEWUSER)`, RTM_NEWLINK/RTM_SETLINK). A purely remote or adjacent peer can generate ARP/NDISC traffic to reach `__neigh_notify()` but cannot cause the namespace pointer to go stale.\nAC:L - The attacker controls both sides: they spin a loop creating/destroying network namespaces with veth devices while concurrently driving neighbour add/update/GC notifications on other CPUs, so the race is created rather than waited for. Per race-condition guidance, attacker-created races are Low even though the window between the `dev_net()` load and the `net-\u003ertnl` dereference is narrow.\nPR:L - `unshare -Urn` grants namespace-relative CAP_NET_ADMIN (`ns_capable(net-\u003euser_ns, CAP_NET_ADMIN)`), letting an ordinary unprivileged user create netns, create and move veth pairs, and trigger the teardown path; no real root is needed. Neighbour-table activity that reaches `__neigh_notify()` is likewise available to any unprivileged process.\nUI:N - The attacker triggers both the namespace teardown and the neighbour notifications entirely from their own processes. No victim action, mount, or file open is involved.\nS:U - The use-after-free and its consequences are confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed. This is standard in-kernel corruption leading to local privilege escalation.\nC:H - The freed `struct net` is a reclaimable `net_cachep` slab object, and `net-\u003ertnl` is subsequently consumed as a `struct sock *` by `netlink_set_err()`/`nlmsg_notify()`, which read `sk-\u003esk_protocol` and `sock_net(sk)` and walk netlink tables from it. Heap-spraying the freed object turns this into an attacker-directed kernel read primitive.\nI:H - With the freed `struct net` reclaimed under attacker control, `netlink_set_err()` writes through the forged `sk` pointer (`sk-\u003esk_err = err`, list/waitqueue manipulation), giving a controlled kernel write usable for control-flow hijacking. Per guidance, use-after-free is scored High for integrity.\nA:H - Even without successful reclaim, dereferencing the freed `struct net` and the dangling `net-\u003ertnl` socket causes a kernel oops or panic in `nlmsg_notify()`/`netlink_set_err()`. The trigger loop can be repeated indefinitely by an unprivileged user."
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Trend slope:
-
(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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