CVE-2026-63912
In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: restore combined single-frag length gate
The ESP out-of-place fast path appends the trailer in esp_output_head() before esp_output_tail() allocates the destination page frag. The head-side gate currently checks skb->data_len and tailen separately, but the tail code allocates a single destination frag from the combined post-trailer skb->data_len.
Reject the page-frag fast path when the combined aligned length exceeds a page. Otherwise skb_page_frag_refill() may fall back to a single page while the destination sg still spans the combined skb->data_len.
Leer descripción completaMostrar menos
Restore this combined-length page gate for both IPv4 and IPv6.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.71%
- Percentil entre todas las CVEs puntuadas: 52
- 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
T1190Exploit Public-Facing Applicationinitial access85 %
Vulnerabilidad remota sin autenticación en kernel Linux (AV:N, PR:N, UI:N) en ESP/XFRM que permite explotación directa. La falta de validación de longitud de fragmento permite DoS o corrupción de memoria en destino.
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/322e48187e0245ab2fff6fec2220b0cae677dbec
- https://git.kernel.org/stable/c/36519e3d941fc99d3b52c134dbaf311f987a4708
- https://git.kernel.org/stable/c/566295735530ee513326049b0540f32ec050bf2e
- https://git.kernel.org/stable/c/5d7ab86e2b6bc23054616bf6ac562013bf60af8c
- https://git.kernel.org/stable/c/65f3b3fc2347b89fe21db1e92c7681368415f095
- https://git.kernel.org/stable/c/b84091ceddc9f133229dceab3ccc930bf27f9cba
- https://git.kernel.org/stable/c/c093468aea8277f77272a4f199b2e15e19cabb59
- https://git.kernel.org/stable/c/dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-63912",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
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{
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{
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],
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"defaultStatus": "unaffected"
},
{
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"vendor": "Linux",
"product": "Linux",
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{
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{
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{
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{
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},
{
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},
{
"status": "unaffected",
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},
{
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},
{
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},
{
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}
],
"programFiles": [
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"net/ipv6/esp6.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T16:17:09.097",
"references": [
{
"url": "https://git.kernel.org/stable/c/322e48187e0245ab2fff6fec2220b0cae677dbec",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/b84091ceddc9f133229dceab3ccc930bf27f9cba",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c093468aea8277f77272a4f199b2e15e19cabb59",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Awaiting Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: esp: restore combined single-frag length gate\n\nThe ESP out-of-place fast path appends the trailer in esp_output_head()\nbefore esp_output_tail() allocates the destination page frag. The\nhead-side gate currently checks skb->data_len and tailen separately, but\nthe tail code allocates a single destination frag from the combined\npost-trailer skb->data_len.\n\nReject the page-frag fast path when the combined aligned length exceeds a\npage. Otherwise skb_page_frag_refill() may fall back to a single page while\nthe destination sg still spans the combined skb->data_len.\n\nRestore this combined-length page gate for both IPv4 and IPv6."
}
],
"lastModified": "2026-07-27T17:44:23.777",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}