CVE-2026-53365
In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: fix zerocopy completion for multi-skb sends
When a large message is fragmented into multiple skbs, the zerocopy uarg is only allocated and attached to the last skb in the loop. Non-final skbs carry pinned user pages with no completion tracking, so the kernel has no way to notify userspace when those pages are safe to reuse. If the loop breaks early the uarg is never allocated at all, leaking pinned pages with no completion notification.
Fix this by following the approach used by TCP: allocate the zerocopy uarg (if not provided by the caller) before the send loop and attach it to every skb via skb_zcopy_set(), which takes a reference per skb.
Leer descripción completaMostrar menos
Each skb's completion properly decrements the refcount, and the notification only fires after the last skb is freed. On failure, if no data was sent, the uarg is cleanly aborted via net_zcopy_put_abort().
This issue was initially discovered by sashiko while reviewing commit 1cb36e252211 ("vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting") but was pre-existing.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.20%
- Percentil entre todas las CVEs puntuadas: 8
- Fecha de la puntuación: 2/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-401
- CWE-404
Referencias
- https://git.kernel.org/stable/c/293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9
- https://git.kernel.org/stable/c/76b995bc57bd90cb6e954e1966fbd8786da47f0d
- https://git.kernel.org/stable/c/ae38d9179190a956e2a87a69ef1dd6f451b51c4d
- https://git.kernel.org/stable/c/b3155f2b78db21e99256bcf7eb902f24ff6d5338
- https://github.com/MaherAzzouzi/vsockdrop
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-53365",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-53365",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-08-18T03:55:24.397803Z"
}
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "581512a6dc939ef122e49336626ae159f3b8a345",
"lessThan": "293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9",
"versionType": "git"
},
{
"status": "affected",
"version": "581512a6dc939ef122e49336626ae159f3b8a345",
"lessThan": "76b995bc57bd90cb6e954e1966fbd8786da47f0d",
"versionType": "git"
},
{
"status": "affected",
"version": "581512a6dc939ef122e49336626ae159f3b8a345",
"lessThan": "b3155f2b78db21e99256bcf7eb902f24ff6d5338",
"versionType": "git"
},
{
"status": "affected",
"version": "581512a6dc939ef122e49336626ae159f3b8a345",
"lessThan": "ae38d9179190a956e2a87a69ef1dd6f451b51c4d",
"versionType": "git"
}
],
"programFiles": [
"net/vmw_vsock/virtio_transport_common.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/vmw_vsock/virtio_transport_common.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-13T18:16:28.433",
"references": [
{
"url": "https://git.kernel.org/stable/c/293fe8f2d1b5ac464ca16a8eba09571bbbb34ba9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/76b995bc57bd90cb6e954e1966fbd8786da47f0d",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ae38d9179190a956e2a87a69ef1dd6f451b51c4d",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b3155f2b78db21e99256bcf7eb902f24ff6d5338",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://github.com/MaherAzzouzi/vsockdrop",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-401"
}
]
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-404"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/virtio: fix zerocopy completion for multi-skb sends\n\nWhen a large message is fragmented into multiple skbs, the zerocopy\nuarg is only allocated and attached to the last skb in the loop.\nNon-final skbs carry pinned user pages with no completion tracking,\nso the kernel has no way to notify userspace when those pages are safe\nto reuse. If the loop breaks early the uarg is never allocated at all,\nleaking pinned pages with no completion notification.\n\nFix this by following the approach used by TCP: allocate the zerocopy\nuarg (if not provided by the caller) before the send loop and attach\nit to every skb via skb_zcopy_set(), which takes a reference per skb.\nEach skb's completion properly decrements the refcount, and the\nnotification only fires after the last skb is freed.\nOn failure, if no data was sent, the uarg is cleanly aborted via\nnet_zcopy_put_abort().\n\nThis issue was initially discovered by sashiko while reviewing commit\n1cb36e252211 (\"vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting\")\nbut was pre-existing."
}
],
"lastModified": "2026-08-18T14:17:10.330",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "467FBE04-4DD0-4EBF-83E8-3C621589E4ED",
"versionEndExcluding": "6.18.34",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750",
"versionEndExcluding": "7.0.11",
"versionStartIncluding": "6.19"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}