CVE-2026-99999
Noticias y reportajes en Orbitaley
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:
ipv4: validar checksum_start antes de completar la suma de comprobación
Si un paquete con metadatos de suma de comprobación incorrectos llega a la pila ipv4, skb_checksum_help puede corromper la cabecera de red y causar todo tipo de problemas.
Esto fue descubierto e informado por Paulos, y desde entonces otros lo han reproducido de forma independiente.
Realmente no deberíamos permitir la entrada de tales paquetes, pero como medida de defensa en profundidad, también comprobemos antes de completar la suma de comprobación.
Se está preparando una validación más completa en la entrada, pero requiere más trabajo.
Traducción automática del texto original de NVD (en inglés).
CVSS
- Puntuación base
- 9.3
- Versión
- 3.1
- Vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días
- 0.21 %
- Percentil entre todas las CVEs puntuadas
- 11
- Fecha de la puntuación
- 20/10/2026
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).
Exploits públicos
Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.
- Prueba de concepto en GitHub (no verificada) · Lista de pruebas de concepto en GitHub
⚠️ Las pruebas de concepto de GitHub no están verificadas: algunas son falsas o contienen malware. No las ejecute nunca fuera de un laboratorio aislado.
Cobertura en medios
Medios especializados en seguridad que han citado esta CVE:
- Borns IT- und Windows-Blog · Linux: KVM-Schwachstelle PwnEscape (CVE-2026-99999) erlaubt Ausbruch (19/10/2026)
- El Hacker · Vulnerabilidad crítica en Linux KVM permite escape de invitado a anfitrión (19/10/2026)
- The Register · Linux KVM guest-host escape rated critical, may represent a new way to attack penguin-powered networking (19/10/2026)
- El Hacker · Fallo crítico de Linux permite escapar de máquinas virtuales y controlar hosts (16/10/2026)
- The Hacker News · Critical PwnEscape Linux Kernel Vulnerability Lets Guest VMs Read Host Memory (15/10/2026)
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 escalation60 % - Impacto principal
T1565Data Manipulationimpact30 %
El vector AV:L/PR:N/UI:N indica explotación local sin interacción (T1068); el texto solo dice que skb_checksum_help puede corromper la cabecera de red, sin detallar escalada ni ejecución.
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.
CWE
- CWE-20
Referencias
Mostrar las 11 referencias
- https://git.kernel.org/stable/c/0fab003ef4698e0628060a45a48f14b43ba2a40a
- https://git.kernel.org/stable/c/32a8b0adaa18e52aaa0b246b5ffe683075354dbb
- https://git.kernel.org/stable/c/6785011f8b16abf40b1e9d8b2e332232b3e68822
- https://git.kernel.org/stable/c/94524b7b32691de2e2ce162c04d6cbc9106e5cbf
- https://git.kernel.org/stable/c/a464d950f31c89565cbaae038cc60db04fe01956
- https://git.kernel.org/stable/c/a65f69e0f38ffbed1b128029e09097436416dc8b
- https://git.kernel.org/stable/c/c3e33464746166264334641dc850a36eef7e6326
- https://git.kernel.org/stable/c/f3e835af6226f1dd12160cbd696081e9b6155de0
- https://pwn.ai/blog/pwnescape
- https://vercel.com/blog/findings-from-the-1-million-dollar-vercel-sandbox-challenge
- http://www.openwall.com/lists/oss-security/2026/10/15/5
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-99999",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-99999",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-10-16T15:49:03.519458Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 9.3,
"attackVector": "LOCAL",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 6,
"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": "f43798c27684ab925adde7d8acc34c78c6e50df8",
"lessThan": "a464d950f31c89565cbaae038cc60db04fe01956",
"versionType": "git"
},
{
"status": "affected",
"version": "f43798c27684ab925adde7d8acc34c78c6e50df8",
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},
{
"status": "affected",
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},
{
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"versionType": "git"
},
{
"status": "affected",
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"lessThan": "32a8b0adaa18e52aaa0b246b5ffe683075354dbb",
"versionType": "git"
},
{
"status": "affected",
"version": "f43798c27684ab925adde7d8acc34c78c6e50df8",
"lessThan": "f3e835af6226f1dd12160cbd696081e9b6155de0",
"versionType": "git"
},
{
"status": "affected",
"version": "f43798c27684ab925adde7d8acc34c78c6e50df8",
"lessThan": "c3e33464746166264334641dc850a36eef7e6326",
"versionType": "git"
},
{
"status": "affected",
"version": "f43798c27684ab925adde7d8acc34c78c6e50df8",
"lessThan": "6785011f8b16abf40b1e9d8b2e332232b3e68822",
"versionType": "git"
}
],
"programFiles": [
"include/net/ip.h",
"net/bridge/netfilter/nf_conntrack_bridge.c",
"net/ipv4/ip_output.c",
"net/netfilter/nfnetlink_queue.c",
"net/netfilter/xt_CHECKSUM.c",
"net/xfrm/xfrm_output.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.27"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.27",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.272",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.223",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.190",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.159",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.57",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.11",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/ip.h",
"net/bridge/netfilter/nf_conntrack_bridge.c",
"net/ipv4/ip_output.c",
"net/netfilter/nfnetlink_queue.c",
"net/netfilter/xt_CHECKSUM.c",
"net/xfrm/xfrm_output.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-15T13:17:14.137",
"references": [
{
"url": "https://git.kernel.org/stable/c/0fab003ef4698e0628060a45a48f14b43ba2a40a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/32a8b0adaa18e52aaa0b246b5ffe683075354dbb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6785011f8b16abf40b1e9d8b2e332232b3e68822",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/94524b7b32691de2e2ce162c04d6cbc9106e5cbf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a464d950f31c89565cbaae038cc60db04fe01956",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a65f69e0f38ffbed1b128029e09097436416dc8b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c3e33464746166264334641dc850a36eef7e6326",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f3e835af6226f1dd12160cbd696081e9b6155de0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://pwn.ai/blog/pwnescape",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://vercel.com/blog/findings-from-the-1-million-dollar-vercel-sandbox-challenge",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "http://www.openwall.com/lists/oss-security/2026/10/15/5",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Received",
"weaknesses": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-20"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: validate checksum_start before completing checksum\n\nIf a packet with bad checksum metadata gets into the ipv4 stack,\nskb_checksum_help can corrupt the network header and cause a bunch of\nmischief.\n\nThis was discovered and reported by Paulos, and has been reporoduced\nby others independently since.\n\nWe really shouldn't allow such packets in, but as a defence\nin depth measure, let's also check before we complete the checksum.\n\nA more complete validation at input is forthcoming, but needs more work."
}
],
"lastModified": "2026-10-19T22:17:28.667",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}