CVE-2026-80838 (GCVE-0-2026-80838)
Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-09-04 15:54
VLAI
EPSS
VEX
Title
vxlan: keep the last remote linked during FDB flush
Summary
In the Linux kernel, the following vulnerability has been resolved:
vxlan: keep the last remote linked during FDB flush
A non-nexthop FDB entry is expected to have at least one remote while it
remains reachable through the FDB hash table. A filtered bulk flush
violates this invariant when every remote matches: It unlinks the last
remote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()
to destroy the parent FDB entry.
An RCU reader can find the parent during this interval.
first_remote_rcu() then applies list_entry_rcu() to the empty list head,
producing an invalid remote pointer that the receive learning path can
read from and write to.
When a matching remote is the sole remaining remote, leave it linked and
ask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps
the remote attached while sending the deletion notification and removing
the parent from the lookup structures.
Severity
No CVSS data available.
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 2a7c2f00843225d5f037676bca649321f3d024c7
(git)
Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < a8820c8a7718327e96849782033e7c85a0f6bcfe (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < d5d4a7b538b52db63927773a8905fcd9f78a42e2 (git) |
|
| Linux | Linux |
Affected:
6.7
Unaffected: 0 , < 6.7 (semver) Unaffected: 6.12.108 , ≤ 6.12.* (semver) Unaffected: 6.18.49 , ≤ 6.18.* (semver) Unaffected: 7.1.13 , ≤ 7.1.* (semver) Unaffected: 7.2.3 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix) |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2a7c2f00843225d5f037676bca649321f3d024c7",
"status": "affected",
"version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
"versionType": "git"
},
{
"lessThan": "a8820c8a7718327e96849782033e7c85a0f6bcfe",
"status": "affected",
"version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
"versionType": "git"
},
{
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"status": "affected",
"version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
"versionType": "git"
},
{
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"status": "affected",
"version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"lessThan": "6.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.108",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.49",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.13",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.3",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc1",
"versionStartIncluding": "6.7",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash table. A filtered bulk flush\nviolates this invariant when every remote matches: It unlinks the last\nremote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()\nto destroy the parent FDB entry.\n\nAn RCU reader can find the parent during this interval.\nfirst_remote_rcu() then applies list_entry_rcu() to the empty list head,\nproducing an invalid remote pointer that the receive learning path can\nread from and write to.\n\nWhen a matching remote is the sole remaining remote, leave it linked and\nask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps\nthe remote attached while sending the deletion notification and removing\nthe parent from the lookup structures."
}
],
"providerMetadata": {
"dateUpdated": "2026-09-04T15:54:48.371Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7"
},
{
"url": "https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe"
},
{
"url": "https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c"
},
{
"url": "https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab"
},
{
"url": "https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"
}
],
"title": "vxlan: keep the last remote linked during FDB flush",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80838",
"datePublished": "2026-09-04T15:54:48.371Z",
"dateReserved": "2026-08-26T14:34:25.796Z",
"dateUpdated": "2026-09-04T15:54:48.371Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-80838",
"date": "2026-10-01",
"epss": "0.00209",
"percentile": "0.09992"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"versionType": "git"
},
{
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"versionType": "git"
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{
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"versionType": "git"
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{
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],
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"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"lessThan": "6.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "7.2.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash table. A filtered bulk flush\nviolates this invariant when every remote matches: It unlinks the last\nremote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()\nto destroy the parent FDB entry.\n\nAn RCU reader can find the parent during this interval.\nfirst_remote_rcu() then applies list_entry_rcu() to the empty list head,\nproducing an invalid remote pointer that the receive learning path can\nread from and write to.\n\nWhen a matching remote is the sole remaining remote, leave it linked and\nask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps\nthe remote attached while sending the deletion notification and removing\nthe parent from the lookup structures."
}
],
"id": "CVE-2026-80838",
"lastModified": "2026-09-04T16:18:12.183",
"metrics": {},
"published": "2026-09-04T16:18:12.183",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
}
}
}
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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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