CVE-2026-74713
In the Linux kernel, the following vulnerability has been resolved:
vhost_iotlb: bound map allocation in add_range
vhost_iotlb_add_range_ctx() only retires an old entry when the table has a non-zero limit, has exactly reached that limit and has VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating entries after reaching their configured limit.
Existing vhost devices allocate their IOTLB with max_iotlb_entries from vhost.c, which defaults to 2048 and is tunable by module parameter. Use the caller-provided limit at the allocation point instead of adding a separate default in the common IOTLB helper, and reject non-positive values in vhost paths that can report an error.
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Other vhost IOTLB users should not create zero-limit tables when entries can be populated from userspace or guest-controlled requests. Add caller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and vhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require at least two entries for vdpa_sim and mlx5 vDPA paths that install full-range mappings, since those mappings are split into two IOTLB entries.
Handle full-range mappings in the common helper by checking that the IOTLB can hold both split entries before inserting the first half. This avoids returning an error after leaving a half mapping behind.
When the table is full, keep the existing retire behavior for retiring tables and return -ENOSPC for non-retiring tables. Reuse the retired map node instead of freeing it and allocating a replacement, so a stream of IOTLB updates cannot keep forcing GFP_ATOMIC allocations after the table has reached its limit. If a zero-limit IOTLB still reaches the common helper, treat it as a configuration error and return -EINVAL.
I found this bug myself, though the patch was written with AI assistance.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- 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
T1499.004Application or System Exploitationimpact80 %
Vulnerabilidad local de kernel (AV:L, PR:N, UI:N) que permite DoS por agotamiento de memoria (allocation exhaustion) sin interacción del usuario mediante IOTLB unbounded allocation.
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
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-74713",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 4,
"exploitabilityScore": 2.5
}
]
},
"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": "0bbe30668d89ec8a309f28ced6d092c90fb23e8c",
"lessThan": "ae128dd19040ee06a4f8143c7ced4d18080d7a9a",
"versionType": "git"
},
{
"status": "affected",
"version": "0bbe30668d89ec8a309f28ced6d092c90fb23e8c",
"lessThan": "1ed35ac7f3fe2b4396bdd29ac3a7f0ebc0829e94",
"versionType": "git"
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],
"programFiles": [
"drivers/vdpa/mlx5/core/mlx5_vdpa.h",
"drivers/vdpa/mlx5/core/mr.c",
"drivers/vdpa/mlx5/core/resources.c",
"drivers/vdpa/vdpa_sim/vdpa_sim.c",
"drivers/vdpa/vdpa_user/iova_domain.c",
"drivers/vhost/iotlb.c",
"drivers/vhost/vdpa.c",
"drivers/vhost/vhost.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/vdpa/mlx5/core/mlx5_vdpa.h",
"drivers/vdpa/mlx5/core/mr.c",
"drivers/vdpa/mlx5/core/resources.c",
"drivers/vdpa/vdpa_sim/vdpa_sim.c",
"drivers/vdpa/vdpa_user/iova_domain.c",
"drivers/vhost/iotlb.c",
"drivers/vhost/vdpa.c",
"drivers/vhost/vhost.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-22T16:16:46.063",
"references": [
{
"url": "https://git.kernel.org/stable/c/1ed35ac7f3fe2b4396bdd29ac3a7f0ebc0829e94",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ae128dd19040ee06a4f8143c7ced4d18080d7a9a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost_iotlb: bound map allocation in add_range\n\nvhost_iotlb_add_range_ctx() only retires an old entry when the table\nhas a non-zero limit, has exactly reached that limit and has\nVHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating\nentries after reaching their configured limit.\n\nExisting vhost devices allocate their IOTLB with max_iotlb_entries from\nvhost.c, which defaults to 2048 and is tunable by module parameter. Use\nthe caller-provided limit at the allocation point instead of adding a\nseparate default in the common IOTLB helper, and reject non-positive\nvalues in vhost paths that can report an error.\n\nOther vhost IOTLB users should not create zero-limit tables when entries\ncan be populated from userspace or guest-controlled requests. Add\ncaller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and\nvhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require\nat least two entries for vdpa_sim and mlx5 vDPA paths that install\nfull-range mappings, since those mappings are split into two IOTLB\nentries.\n\nHandle full-range mappings in the common helper by checking that the\nIOTLB can hold both split entries before inserting the first half. This\navoids returning an error after leaving a half mapping behind.\n\nWhen the table is full, keep the existing retire behavior for retiring\ntables and return -ENOSPC for non-retiring tables. Reuse the retired map\nnode instead of freeing it and allocating a replacement, so a stream of\nIOTLB updates cannot keep forcing GFP_ATOMIC allocations after the table\nhas reached its limit. If a zero-limit IOTLB still reaches the common\nhelper, treat it as a configuration error and return -EINVAL.\n\nI found this bug myself, though the patch was written with AI assistance."
}
],
"lastModified": "2026-08-25T06:18:56.500",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}