CVE-2026-64026
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg
This improves the fix for CVE-2026-43500.
Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent) then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains unmodified.
This has an additional advantage in that the packet is then arranged in the buffer with the correct alignment required for the crypto algorithms to process directly.
Leer descripción completaMostrar menos
The performance of the crypto does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much - possibly due to removing complexity from the I/O thread.
Yet another advantage is that the I/O thread doesn't have to copy packets which would slow down packet distribution, ACK generation, etc..
The buffer belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket, but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a subsequent recvmsg().
Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to using USHRT_MAX to indicate an invalid offset.
Note also that I would generally prefer to replace the buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to have to allocate a new sk_buff.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.18%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 6/10/2026
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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1565.001Stored Data Manipulationimpact75 % - Impacto secundario
T1499.004Application or System Exploitationimpact60 %
Vulnerabilidad local (AV:L/PR:L) que permite corrupción de memoria en kernel Linux mediante decrypt in-place de paquetes rxrpc, escalando a manipulación de datos de caché y potencial DoS.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/46cb765e2e5ad52303ea157e10d370bb6b7acbbf
- https://git.kernel.org/stable/c/a05bf6d9e621fa71e89ccebe3047ba45218d7b38
- https://git.kernel.org/stable/c/b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5
- https://git.kernel.org/stable/c/c580087743712112778a06d65a4074053072d7bf
- https://git.kernel.org/stable/c/d2bc90cf6c75cb96d2ce549be6c35efa3099d25b
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64026",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"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": "d0d5c0cd1e711c98703f3544c1e6fc1372898de5",
"lessThan": "a05bf6d9e621fa71e89ccebe3047ba45218d7b38",
"versionType": "git"
},
{
"status": "affected",
"version": "d0d5c0cd1e711c98703f3544c1e6fc1372898de5",
"lessThan": "b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5",
"versionType": "git"
},
{
"status": "affected",
"version": "d0d5c0cd1e711c98703f3544c1e6fc1372898de5",
"lessThan": "46cb765e2e5ad52303ea157e10d370bb6b7acbbf",
"versionType": "git"
},
{
"status": "affected",
"version": "d0d5c0cd1e711c98703f3544c1e6fc1372898de5",
"lessThan": "c580087743712112778a06d65a4074053072d7bf",
"versionType": "git"
},
{
"status": "affected",
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"lessThan": "d2bc90cf6c75cb96d2ce549be6c35efa3099d25b",
"versionType": "git"
}
],
"programFiles": [
"net/rxrpc/ar-internal.h",
"net/rxrpc/call_event.c",
"net/rxrpc/call_object.c",
"net/rxrpc/insecure.c",
"net/rxrpc/recvmsg.c",
"net/rxrpc/rxgk.c",
"net/rxrpc/rxgk_common.h",
"net/rxrpc/rxkad.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.35",
"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/rxrpc/ar-internal.h",
"net/rxrpc/call_event.c",
"net/rxrpc/call_object.c",
"net/rxrpc/insecure.c",
"net/rxrpc/recvmsg.c",
"net/rxrpc/rxgk.c",
"net/rxrpc/rxgk_common.h",
"net/rxrpc/rxkad.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T16:17:42.643",
"references": [
{
"url": "https://git.kernel.org/stable/c/46cb765e2e5ad52303ea157e10d370bb6b7acbbf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a05bf6d9e621fa71e89ccebe3047ba45218d7b38",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c580087743712112778a06d65a4074053072d7bf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d2bc90cf6c75cb96d2ce549be6c35efa3099d25b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Awaiting Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg\n\nThis improves the fix for CVE-2026-43500.\n\nFix the pagecache corruption from in-place decryption of a DATA packet\ntransmitted locally by splice() by getting rid of the packet sharing in the\nI/O thread and unconditionally extracting the packet content into a bounce\nbuffer in which the buffer is decrypted. recvmsg() (or the kernel\nequivalent) then copies the data from the bounce buffer to the destination\nbuffer. The sk_buff then remains unmodified.\n\nThis has an additional advantage in that the packet is then arranged in the\nbuffer with the correct alignment required for the crypto algorithms to\nprocess directly. The performance of the crypto does seem to be a little\nfaster and, surprisingly, the unencrypted performance doesn't seem to\nchange much - possibly due to removing complexity from the I/O thread.\n\nYet another advantage is that the I/O thread doesn't have to copy packets\nwhich would slow down packet distribution, ACK generation, etc..\n\nThe buffer belongs to the call and is allocated initially at 2K,\nsufficiently large to hold a whole jumbo subpacket, but the buffer will be\nincreased in size if needed. However, to take this work, MSG_PEEK may\ncause a later packet to be decrypted into the buffer, in which case the\nearlier one will need re-decrypting for a subsequent recvmsg().\n\nNote that rx_pkt_offset may legitimately see 0 as a valid offset now, so\nswitch to using USHRT_MAX to indicate an invalid offset.\n\nNote also that I would generally prefer to replace the buffers of the\ncurrent sk_buff with a new kmalloc'd buffer of the right size, ditching the\nold data and frags as this makes the handling of MSG_PEEK easier and\nremoves the re-decryption issue, but this looks like quite a complicated\nthing to achieve. skb_morph() looks half way to what I want, but I don't\nwant to have to allocate a new sk_buff."
}
],
"lastModified": "2026-07-30T14:59:47.950",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}