CVE-2026-64436
Estado: AnalizadaAlta (7.1)—
In the Linux kernel, the following vulnerability has been resolved:
net: af_key: initialize alg_key_len for IPComp states
pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by allocating x->calg and copying only the algorithm name:
Unlike the authentication (x->aalg) and encryption (x->ealg) branches of the same function, the compression branch never initializes calg->alg_key_len. IPComp carries no key and the allocation only reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field is left containing uninitialized slab data.
calg->alg_key_len is later used as a length by xfrm_algo_clone() when an IPComp state is cloned during XFRM_MSG_MIGRATE:
Leer descripción completaMostrar menos
where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With a non-zero garbage alg_key_len, kmemdup() reads past the end of the 68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating it triggers (net-next, KASAN, init_on_alloc=0):
Depending on the uninitialized value the same field can instead request an oversized kmemdup() allocation and make the migration clone fail.
The XFRM netlink path is not affected: verify_one_alg() rejects an XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via XFRM_MSG_NEWSA is always self-consistent.
Initialize calg->alg_key_len to 0, matching the aalg/ealg branches.
Detalles técnicos trazas, registros y código del informe original
x->calg = kmalloc_obj(*x->calg);
if (!x->calg) {
err = -ENOMEM;
goto out;
}
strcpy(x->calg->alg_name, a->name);
x->props.calgo = sa->sadb_sa_encrypt;
xfrm_state_migrate()
xfrm_state_clone_and_setup()
x->calg = xfrm_algo_clone(orig->calg);
kmemdup(orig, xfrm_alg_len(orig));
BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60
Read of size 4164 at addr ff11000025a74980 by task diag2/9287
CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1
Call Trace:
<TASK>
dump_stack_lvl+0x10e/0x1f0
print_report+0xf7/0x600
kasan_report+0xe4/0x120
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x23/0x60
kmemdup_noprof+0x44/0x60
xfrm_state_migrate+0x70a/0x1da0
xfrm_migrate+0x753/0x18a0
xfrm_do_migrate+0xb47/0xf10
xfrm_user_rcv_msg+0x411/0xb50
netlink_rcv_skb+0x158/0x420
xfrm_netlink_rcv+0x71/0x90
netlink_unicast+0x584/0x850
netlink_sendmsg+0x8b0/0xdc0
____sys_sendmsg+0x9f7/0xb90
___sys_sendmsg+0x134/0x1d0
__sys_sendmsg+0x16d/0x220
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 9287:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
pfkey_add+0x2652/0x2ea0
pfkey_process+0x6d0/0x830
pfkey_sendmsg+0x42c/0x850
__sys_sendto+0x461/0x4b0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ff11000025a74980
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
allocated 68-byte region [ff11000025a74980, ff11000025a749c4)CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- 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
T1059Command and Scripting Interpreterexecution70 % - Impacto secundario
T1499.004Application or System Exploitationimpact60 %
Vulnerabilidad local (AV:L, PR:L) sin interacción que causa lectura de memoria no inicializada en el kernel Linux, permitiendo escalada de privilegios o denegación de servicio mediante XFRM netlink.
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)
CWE
- CWE-125
Referencias
- https://git.kernel.org/stable/c/01b9115b55018123ef2449ac4951f89147a8428e
- https://git.kernel.org/stable/c/273c06b81d2e902b21acc801ae18c8276c8a9b69
- https://git.kernel.org/stable/c/3f63d1752d90c0e28be931a48ab5d89bc97d637d
- https://git.kernel.org/stable/c/58e82fc3dedb57b1432292504415b224fd2d6acb
- https://git.kernel.org/stable/c/6de2a650917bedaaefd65b17cede83c5e2c1dedd
- https://git.kernel.org/stable/c/cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e
- https://git.kernel.org/stable/c/d129c3177d7b1138fd5066fcc63a698b3ba415b0
- https://git.kernel.org/stable/c/e8417353cbd078d10531ba3928e609c84ab09e6b
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64436",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"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": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "58e82fc3dedb57b1432292504415b224fd2d6acb",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "01b9115b55018123ef2449ac4951f89147a8428e",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "3f63d1752d90c0e28be931a48ab5d89bc97d637d",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "273c06b81d2e902b21acc801ae18c8276c8a9b69",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "6de2a650917bedaaefd65b17cede83c5e2c1dedd",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "e8417353cbd078d10531ba3928e609c84ab09e6b",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e",
"versionType": "git"
},
{
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"lessThan": "d129c3177d7b1138fd5066fcc63a698b3ba415b0",
"versionType": "git"
}
],
"programFiles": [
"net/key/af_key.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.21"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.21",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/key/af_key.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-25T10:17:28.010",
"references": [
{
"url": "https://git.kernel.org/stable/c/01b9115b55018123ef2449ac4951f89147a8428e",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/273c06b81d2e902b21acc801ae18c8276c8a9b69",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3f63d1752d90c0e28be931a48ab5d89bc97d637d",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/58e82fc3dedb57b1432292504415b224fd2d6acb",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6de2a650917bedaaefd65b17cede83c5e2c1dedd",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d129c3177d7b1138fd5066fcc63a698b3ba415b0",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e8417353cbd078d10531ba3928e609c84ab09e6b",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: af_key: initialize alg_key_len for IPComp states\n\npfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by\nallocating x->calg and copying only the algorithm name:\n\n\tx->calg = kmalloc_obj(*x->calg);\n\tif (!x->calg) {\n\t\terr = -ENOMEM;\n\t\tgoto out;\n\t}\n\tstrcpy(x->calg->alg_name, a->name);\n\tx->props.calgo = sa->sadb_sa_encrypt;\n\nUnlike the authentication (x->aalg) and encryption (x->ealg) branches of\nthe same function, the compression branch never initializes\ncalg->alg_key_len. IPComp carries no key and the allocation only\nreserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field\nis left containing uninitialized slab data.\n\ncalg->alg_key_len is later used as a length by xfrm_algo_clone() when an\nIPComp state is cloned during XFRM_MSG_MIGRATE:\n\n\txfrm_state_migrate()\n\t xfrm_state_clone_and_setup()\n\t x->calg = xfrm_algo_clone(orig->calg);\n\t kmemdup(orig, xfrm_alg_len(orig));\n\nwhere xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With\na non-zero garbage alg_key_len, kmemdup() reads past the end of the\n68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating\nit triggers (net-next, KASAN, init_on_alloc=0):\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60\n Read of size 4164 at addr ff11000025a74980 by task diag2/9287\n CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1\n Call Trace:\n <TASK>\n dump_stack_lvl+0x10e/0x1f0\n print_report+0xf7/0x600\n kasan_report+0xe4/0x120\n kasan_check_range+0x105/0x1b0\n __asan_memcpy+0x23/0x60\n kmemdup_noprof+0x44/0x60\n xfrm_state_migrate+0x70a/0x1da0\n xfrm_migrate+0x753/0x18a0\n xfrm_do_migrate+0xb47/0xf10\n xfrm_user_rcv_msg+0x411/0xb50\n netlink_rcv_skb+0x158/0x420\n xfrm_netlink_rcv+0x71/0x90\n netlink_unicast+0x584/0x850\n netlink_sendmsg+0x8b0/0xdc0\n ____sys_sendmsg+0x9f7/0xb90\n ___sys_sendmsg+0x134/0x1d0\n __sys_sendmsg+0x16d/0x220\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\n Allocated by task 9287:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n pfkey_add+0x2652/0x2ea0\n pfkey_process+0x6d0/0x830\n pfkey_sendmsg+0x42c/0x850\n __sys_sendto+0x461/0x4b0\n __x64_sys_sendto+0xe0/0x1c0\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n The buggy address belongs to the object at ff11000025a74980\n which belongs to the cache kmalloc-96 of size 96\n The buggy address is located 0 bytes inside of\n allocated 68-byte region [ff11000025a74980, ff11000025a749c4)\n\nDepending on the uninitialized value the same field can instead request\nan oversized kmemdup() allocation and make the migration clone fail.\n\nThe XFRM netlink path is not affected: verify_one_alg() rejects an\nXFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via\nXFRM_MSG_NEWSA is always self-consistent.\n\nInitialize calg->alg_key_len to 0, matching the aalg/ealg branches."
}
],
"lastModified": "2026-09-03T18:19:24.283",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B206899A-54DE-4797-A993-B62C1B128204",
"versionEndExcluding": "5.10.261",
"versionStartIncluding": "2.6.21"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8E99FB01-CD93-41AF-A653-3F450652B9A6",
"versionEndExcluding": "5.15.212",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "092233C7-F4E0-40C8-BD4D-A28FE50DFE20",
"versionEndExcluding": "6.1.178",
"versionStartIncluding": "5.16"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7046B092-F810-4440-ACE6-60218518EECE",
"versionEndExcluding": "6.6.145",
"versionStartIncluding": "6.2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "38A8100E-2B1A-462F-AEE9-8901B870FEF2",
"versionEndExcluding": "6.12.96",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7",
"versionEndExcluding": "6.18.39",
"versionStartIncluding": "6.13"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42",
"versionEndExcluding": "7.1.4",
"versionStartIncluding": "6.19"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}