CVE-2026-80961
In the Linux kernel, the following vulnerability has been resolved:
dm-pcache: validate kset key_num and intra-segment bounds
Two more fields decoded from the cache device go unbounded. The kset key_num drives cache_kset_crc() and the replay loop in cache_replay(), the writeback worker and the GC worker, but only the magic and a fixed-seed CRC are checked first, so a non-last kset whose key_num exceeds the PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare.
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A key's intra-segment offset and length in cache_key_decode() are taken verbatim, so a key running past its segment is replayed into the cache tree and the data CRC check and every later read hit then copy adjacent persistent memory into the caller's bio -- an out-of-bounds read that leaks to user space. Both fields are controlled by whoever supplies the cache device (CAP_SYS_ADMIN); the CRC seed is public.
Add kset_onmedia_valid() to bound key_num before any kset read, and reject a key whose offset plus length, computed in 64 bits, exceeds the segment data_size. Valid metadata is unaffected.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 6
- 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 escalation90 % - Impacto principal
T1005Data from Local Systemcollection85 % - Impacto secundario
T1552.007Container APIcredential access80 %
Vulnerabilidad local (AV:L, PR:L) en el kernel Linux que permite leer memoria fuera de límites (out-of-bounds read) en dm-pcache sin validar key_num e intra-segment bounds, causando fuga de datos persistentes al espacio de usuario.
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)
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{
"id": "CVE-2026-80961",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
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"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": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
"lessThan": "d8caf96040a06096276ab72f5e1e8547c014c564",
"versionType": "git"
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{
"status": "affected",
"version": "1d57628ff95b32d5cfa8d8f50e07690c161e9cf0",
"lessThan": "5ac38f4b4862fad6e7270fde5c3356a822ce74ca",
"versionType": "git"
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{
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"lessThan": "f11deb032fd84081e7831cffcba895d893054a22",
"versionType": "git"
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],
"programFiles": [
"drivers/md/dm-pcache/cache.h",
"drivers/md/dm-pcache/cache_gc.c",
"drivers/md/dm-pcache/cache_key.c",
"drivers/md/dm-pcache/cache_writeback.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/md/dm-pcache/cache.h",
"drivers/md/dm-pcache/cache_gc.c",
"drivers/md/dm-pcache/cache_key.c",
"drivers/md/dm-pcache/cache_writeback.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-11T20:19:01.980",
"references": [
{
"url": "https://git.kernel.org/stable/c/5ac38f4b4862fad6e7270fde5c3356a822ce74ca",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d8caf96040a06096276ab72f5e1e8547c014c564",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f11deb032fd84081e7831cffcba895d893054a22",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-pcache: validate kset key_num and intra-segment bounds\n\nTwo more fields decoded from the cache device go unbounded. The kset\nkey_num drives cache_kset_crc() and the replay loop in cache_replay(),\nthe writeback worker and the GC worker, but only the magic and a\nfixed-seed CRC are checked first, so a non-last kset whose key_num exceeds\nthe PCACHE_KSET_KEYS_MAX buffer reads past its end before the CRC compare.\nA key's intra-segment offset and length in cache_key_decode() are taken\nverbatim, so a key running past its segment is replayed into the cache\ntree and the data CRC check and every later read hit then copy adjacent\npersistent memory into the caller's bio -- an out-of-bounds read that\nleaks to user space. Both fields are controlled by whoever supplies the\ncache device (CAP_SYS_ADMIN); the CRC seed is public.\n\nAdd kset_onmedia_valid() to bound key_num before any kset read, and\nreject a key whose offset plus length, computed in 64 bits, exceeds the\nsegment data_size. Valid metadata is unaffected."
}
],
"lastModified": "2026-09-13T07:17:03.070",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}