CVE-2026-80848 (GCVE-0-2026-80848)
Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-10-19 08:44
VLAI
EPSS
VEX
Title
xfrm: espintcp: fix UAF during close
Summary
In the Linux kernel, the following vulnerability has been resolved:
xfrm: espintcp: fix UAF during close
ZDI reported and analyzed a race condition during close for espintcp
sockets:
espintcp_close() frees emsg->skb via kfree_skb() without holding
any socket lock. Concurrently, the xfrm_trans_reinject work queue
invokes esp_output_tcp_finish() -> espintcp_push_skb() ->
espintcp_push_msgs() -> skb_send_sock_locked(), which reads the
same skb as a data source.
Fix this by adding a synchronize_rcu() call after resetting sk_prot,
since esp_output_tcp_finish() runs under RCU and won't use a socket
with sk_prot == &tcp_prot. Simply taking the socket lock in
espintcp_close() could lead to leaks, if esp_output_tcp_finish()
re-adds an skb in the slot we just freed. After this, the existing
barrier() is no longer needed.
Severity
No CVSS data available.
Assigner
References
9 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 29121c5e6591da527e8e36ddac7120dc527f574d
(git)
Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < ed5d9102190c45fc70121c036b0626b740040b75 (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 4bc0dfa28dca6fc0084203732695968049c44072 (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < ff8dd7a932f34409a56e1b91a1219340f17457e9 (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 4b31a875693c480c611519faca46216514e3e052 (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 24efebecf415ba264adba0f0491cec436463a14f (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < eb3bbf29c723fe75c0eb92be14f0ec92971fe272 (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 54b41ad14da9a981131ab6e4d3f79321a503ea5d (git) Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < deb232e884877bf10b4ce2580909eedec986c284 (git) |
guessed | |
| Linux | Linux |
Affected:
5.6
Unaffected: 0 , < 5.6 (semver) Unaffected: 5.10.269 , ≤ 5.10.* (semver) Unaffected: 5.15.220 , ≤ 5.15.* (semver) Unaffected: 6.1.187 , ≤ 6.1.* (semver) Unaffected: 6.6.156 , ≤ 6.6.* (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 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
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{
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"product": "Linux",
"programFiles": [
"net/xfrm/espintcp.c"
],
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"vendor": "Linux",
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},
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],
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"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
"lessThan": "5.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.269",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.220",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.187",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.156",
"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",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.269",
"versionStartIncluding": "5.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.220",
"versionStartIncluding": "5.6",
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},
{
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"vulnerable": true
},
{
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.108",
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},
{
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},
{
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},
{
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"versionStartIncluding": "5.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "5.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: espintcp: fix UAF during close\n\nZDI reported and analyzed a race condition during close for espintcp\nsockets:\n\n espintcp_close() frees emsg-\u003eskb via kfree_skb() without holding\n any socket lock. Concurrently, the xfrm_trans_reinject work queue\n invokes esp_output_tcp_finish() -\u003e espintcp_push_skb() -\u003e\n espintcp_push_msgs() -\u003e skb_send_sock_locked(), which reads the\n same skb as a data source.\n\nFix this by adding a synchronize_rcu() call after resetting sk_prot,\nsince esp_output_tcp_finish() runs under RCU and won\u0027t use a socket\nwith sk_prot == \u0026tcp_prot. Simply taking the socket lock in\nespintcp_close() could lead to leaks, if esp_output_tcp_finish()\nre-adds an skb in the slot we just freed. After this, the existing\nbarrier() is no longer needed."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T08:44:42.445Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/29121c5e6591da527e8e36ddac7120dc527f574d"
},
{
"url": "https://git.kernel.org/stable/c/ed5d9102190c45fc70121c036b0626b740040b75"
},
{
"url": "https://git.kernel.org/stable/c/4bc0dfa28dca6fc0084203732695968049c44072"
},
{
"url": "https://git.kernel.org/stable/c/ff8dd7a932f34409a56e1b91a1219340f17457e9"
},
{
"url": "https://git.kernel.org/stable/c/4b31a875693c480c611519faca46216514e3e052"
},
{
"url": "https://git.kernel.org/stable/c/24efebecf415ba264adba0f0491cec436463a14f"
},
{
"url": "https://git.kernel.org/stable/c/eb3bbf29c723fe75c0eb92be14f0ec92971fe272"
},
{
"url": "https://git.kernel.org/stable/c/54b41ad14da9a981131ab6e4d3f79321a503ea5d"
},
{
"url": "https://git.kernel.org/stable/c/deb232e884877bf10b4ce2580909eedec986c284"
}
],
"title": "xfrm: espintcp: fix UAF during close",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80848",
"datePublished": "2026-09-04T15:54:58.427Z",
"dateReserved": "2026-08-26T14:34:25.797Z",
"dateUpdated": "2026-10-19T08:44:42.445Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-80848",
"date": "2026-11-09",
"epss": "0.00195",
"percentile": "0.09258"
},
"microsoft_vex": {
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"cve": "CVE-2026-80848",
"id": "msrc_CVE-2026-80848",
"initial_release_date": "2026-09-07T01:50:52.000Z",
"product_status:known_not_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "xfrm: espintcp: fix UAF during close",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-80848.json",
"version": "2"
},
"nvd": {
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"product": "Linux",
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],
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},
{
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{
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{
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"versionType": "git"
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{
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"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
},
{
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},
{
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}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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{
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{
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"versionType": "semver"
},
{
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},
{
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},
{
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},
{
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"version": "6.12.108",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
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"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",
"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\nxfrm: espintcp: fix UAF during close\n\nZDI reported and analyzed a race condition during close for espintcp\nsockets:\n\n espintcp_close() frees emsg-\u003eskb via kfree_skb() without holding\n any socket lock. Concurrently, the xfrm_trans_reinject work queue\n invokes esp_output_tcp_finish() -\u003e espintcp_push_skb() -\u003e\n espintcp_push_msgs() -\u003e skb_send_sock_locked(), which reads the\n same skb as a data source.\n\nFix this by adding a synchronize_rcu() call after resetting sk_prot,\nsince esp_output_tcp_finish() runs under RCU and won\u0027t use a socket\nwith sk_prot == \u0026tcp_prot. Simply taking the socket lock in\nespintcp_close() could lead to leaks, if esp_output_tcp_finish()\nre-adds an skb in the slot we just freed. After this, the existing\nbarrier() is no longer needed."
}
],
"id": "CVE-2026-80848",
"lastModified": "2026-10-19T09:17:20.307",
"metrics": {},
"published": "2026-09-04T16:18:13.540",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/24efebecf415ba264adba0f0491cec436463a14f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/29121c5e6591da527e8e36ddac7120dc527f574d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4b31a875693c480c611519faca46216514e3e052"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4bc0dfa28dca6fc0084203732695968049c44072"
},
{
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"url": "https://git.kernel.org/stable/c/54b41ad14da9a981131ab6e4d3f79321a503ea5d"
},
{
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"url": "https://git.kernel.org/stable/c/deb232e884877bf10b4ce2580909eedec986c284"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/eb3bbf29c723fe75c0eb92be14f0ec92971fe272"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ed5d9102190c45fc70121c036b0626b740040b75"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ff8dd7a932f34409a56e1b91a1219340f17457e9"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-11-04T23:36:07+00:00",
"cve": "CVE-2026-80848",
"id": "CVE-2026-80848",
"initial_release_date": "2026-09-04T00:00:00+00:00",
"product_status:known_affected": "161",
"product_status:known_not_affected": "42",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: xfrm: espintcp: fix UAF during close",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80848.json",
"version": "3"
}
}
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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How durations are calculated
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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.