CVE-2026-98839
Estado: RecibidaSin puntuar—
Gravedad—Sin puntuar
Probabilidad de explotación0.17 %mayor que el 5 % de las CVE
Explotación activaNono figura en el catálogo de CISA
Exploit públicoNo conocidosin código público localizado
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:
vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()
En paste_selection(), el bucle copia min_t(unsigned int, vc_sel.buf_len - pasted, tty->receive_room) bytes en cada iteración hacia tty_ldisc_receive_buf() e incrementa pasted += count.
Dado que el mutex de selección (vc_sel.lock) se libera dentro del bucle, cuando el búfer de la disciplina de línea se llena y paste_selection() se suspende en tty->write_wait, un ioctl TIOCLINUX (TIOCL_SETSEL) concurrente puede sustituir vc_sel.buffer por una selección más corta y reducir vc_sel.buf_len por debajo de pasted.
Leer descripción completaMostrar menos
Cuando paste_selection() se reanuda, vc_sel.buf_len - pasted sufre un desbordamiento negativo (underflow) como entero sin signo, dando un valor positivo muy grande, lo que provoca que tty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, count) lea hasta 4094 bytes fuera de los límites, más allá del vc_sel.buffer recién asignado.
Para corregirlo, se termina el bucle cuando pasted >= vc_sel.buf_len.
Detalles técnicos trazas, registros y código del informe original
Traza de pila del kernel (Linux 7.3.0-rc3): ================================================================== BUG: KASAN: slab-out-of-bounds in n_tty_receive_buf_common+0xa01/0x1650 Read of size 4094 at addr ffff888101c58010 by task kworker/u17:1/65 Workqueue: events_unbound flush_to_ldisc Call Trace: <TASK> dump_stack_lvl+0x70/0xa0 print_report+0x153/0x4c6 kasan_report+0xf1/0x120 kasan_check_range+0x11c/0x200 __asan_memcpy+0x29/0x70 n_tty_receive_buf_common+0xa01/0x1650 tty_ldisc_receive_buf+0x66/0x110 tty_port_default_receive_buf+0x6b/0xb0 flush_to_ldisc+0x1b4/0x410 process_one_work+0x6ff/0x1110 worker_thread+0x4a8/0xb70 kthread+0x307/0x3e0 ret_from_fork+0x3ed/0x680 </TASK> ==================================================================
Traducción automática del texto original de NVD (en inglés).
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días
- 0.17 %
- Percentil entre todas las CVEs puntuadas
- 5
- 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).
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-2026-98839",
"cveTags": [],
"metrics": {},
"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": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "037d7e3ca5c593092f4b0d471eb869a85cbddde0",
"versionType": "git"
},
{
"status": "affected",
"version": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "619c6d7dd76fff15a9714fbf02ce299b737f01a2",
"versionType": "git"
},
{
"status": "affected",
"version": "e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2",
"lessThan": "39495ef5d6f8019e62d65807f217a7ca8232727a",
"versionType": "git"
},
{
"status": "affected",
"version": "54c522782fd11a720f959ee9cb5a15bb9580343d",
"versionType": "git"
},
{
"status": "affected",
"version": "05c508edc9d0b44e4706d3c2cf14ee12aac210d2",
"versionType": "git"
},
{
"status": "affected",
"version": "e5be0e24ffc7f5783a3864b5b958088ed15be9e8",
"versionType": "git"
},
{
"status": "affected",
"version": "a4719f6d07b2c63223f7452c435c5f578f105cfe",
"versionType": "git"
},
{
"status": "affected",
"version": "b4492f1e7456bd162714c0ec2815c2749d930844",
"versionType": "git"
},
{
"status": "affected",
"version": "9a9c13ad21a8220cb70c9807a920f43520515f94",
"versionType": "git"
},
{
"status": "affected",
"version": "8c368d36878e2fc99285279fc5e14b3d3cb8947c",
"versionType": "git"
},
{
"status": "affected",
"version": "3.16.83",
"lessThan": "3.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.4.216",
"lessThan": "4.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.216",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.173",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.109",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.25",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.5.9",
"lessThan": "5.6",
"versionType": "semver"
}
],
"programFiles": [
"drivers/tty/vt/selection.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/tty/vt/selection.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:38.170",
"references": [
{
"url": "https://git.kernel.org/stable/c/037d7e3ca5c593092f4b0d471eb869a85cbddde0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/39495ef5d6f8019e62d65807f217a7ca8232727a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/619c6d7dd76fff15a9714fbf02ce299b737f01a2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()\n\nIn paste_selection(), the loop copies min_t(unsigned int,\nvc_sel.buf_len - pasted,tty->receive_room) bytes per iteration into\ntty_ldisc_receive_buf() and increments pasted += count.\n\nBecause the selection mutex (vc_sel.lock) is dropped inside the loop\nWhenever the line discipline buffer fills up and paste_selection()\nsleeps on tty->write_wait, a concurrent TIOCLINUX (TIOCL_SETSEL) ioctl\ncan replace vc_sel.buffer with a shorter selection and reduce\nvc_sel.buf_len below pasted.\n\nWhen paste_selection() resumes, vc_sel.buf_len - pasted underflows as an\nunsigned integer to a large positive value, causing\ntty_ldisc_receive_buf(ld, vc_sel.buffer + pasted, NULL, count) to read\nup to 4094 bytes out-of-bounds past the newly allocated vc_sel.buffer.\n\nFix this by terminating the loop when pasted >= vc_sel.buf_len.\n\nKernel stack trace (Linux 7.3.0-rc3):\n ==================================================================\n BUG: KASAN: slab-out-of-bounds in n_tty_receive_buf_common+0xa01/0x1650\n Read of size 4094 at addr ffff888101c58010 by task kworker/u17:1/65\n Workqueue: events_unbound flush_to_ldisc\n Call Trace:\n <TASK>\n dump_stack_lvl+0x70/0xa0\n print_report+0x153/0x4c6\n kasan_report+0xf1/0x120\n kasan_check_range+0x11c/0x200\n __asan_memcpy+0x29/0x70\n n_tty_receive_buf_common+0xa01/0x1650\n tty_ldisc_receive_buf+0x66/0x110\n tty_port_default_receive_buf+0x6b/0xb0\n flush_to_ldisc+0x1b4/0x410\n process_one_work+0x6ff/0x1110\n worker_thread+0x4a8/0xb70\n kthread+0x307/0x3e0\n ret_from_fork+0x3ed/0x680\n </TASK>\n =================================================================="
}
],
"lastModified": "2026-10-19T10:19:47.957",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}