CVE-2026-98255
In the Linux kernel, the following vulnerability has been resolved:
tcp: exclude old ACKs from tcp fast path
Exclude old ACKs before SND.UNA from the tcp fast path as well as ACKs after SND.NXT.
Such ACKs will fall through to the slow path, where tcp_ack() performs the appropriate validation and challenge ACK handling according to RFC5961 and Commit 3d501dd326fb1c7 ("tcp: do not accept ACK of bytes we never sent").
This prevents old ACKs from being accepted or modifying connection state as part of the fast path before appropriate ACK validation is applied. In particular, this prevents payload carried by a segment with an excessively old ACK from advancing RCV.NXT before the ACK is rejected.
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: 0.18%
- Percentil entre todas las CVEs puntuadas: 7
- 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).
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/07cacab90290f795bad2e566790f4ba8e84cdf5f
- https://git.kernel.org/stable/c/1c8448db5cf35a13d82b0c9004ffdb49358883e7
- https://git.kernel.org/stable/c/6eb9b697f50b73b9684e466c1e97f4ca8e947a59
- https://git.kernel.org/stable/c/8205ac5ddb42a1843fa8d6a8c295b5c7f4f8c6ed
- https://git.kernel.org/stable/c/8309dc2cc360056aa9cd2acfbfc25930798c3b66
- https://git.kernel.org/stable/c/b86e1e5a4bbcbbccde8b7a3d3486604b581f6628
- https://git.kernel.org/stable/c/f81e6c3fb06327bc49cdd6e559845293ba06a704
- https://git.kernel.org/stable/c/ff037920c688ae6ca1153fec01e90e6782712455
JSON original (NVD)
Mostrar
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"id": "CVE-2026-98255",
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"metrics": {},
"affected": [
{
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{
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{
"status": "unaffected",
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{
"status": "unaffected",
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"versionType": "semver",
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{
"status": "unaffected",
"version": "6.1.189",
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{
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"version": "6.6.158",
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{
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"version": "6.12.112",
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{
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{
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"published": "2026-10-06T09:18:14.210",
"references": [
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/b86e1e5a4bbcbbccde8b7a3d3486604b581f6628",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ff037920c688ae6ca1153fec01e90e6782712455",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: exclude old ACKs from tcp fast path\n\nExclude old ACKs before SND.UNA from the tcp fast path\nas well as ACKs after SND.NXT.\n\nSuch ACKs will fall through to the slow path, where tcp_ack()\nperforms the appropriate validation and challenge ACK handling\naccording to RFC5961 and Commit 3d501dd326fb1c7 (\"tcp: do not\naccept ACK of bytes we never sent\").\n\nThis prevents old ACKs from being accepted\nor modifying connection state as part of the fast path before\nappropriate ACK validation is applied.\nIn particular, this prevents payload carried by a segment with\nan excessively old ACK from advancing RCV.NXT before the ACK\nis rejected."
}
],
"lastModified": "2026-10-06T09:18:14.210",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}