CVE-2026-98299Network attack vector

Kernel crash via undersized TCP receive buffer

Published Oct 6, 2026 · Updated Oct 6, 2026

Denial of service in Linux kernel TCP receive-buffer handling allows remote attackers to crash a host via TCP data when tcp_rmem is set below 4096. The tcp_rmem sysctl accepts a value that makes tcp_full_space truncate to zero; tcp_rcvbuf_grow then divides by the zero receive-space value during buffer growth. The crash requires an unusually small, locally configured tcp_rmem value and a TCP connection that reaches receive-buffer growth.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel TCP receive-buffer handling allows remote attackers to crash a host via TCP data when tcp_rmem is set below 4096. The tcp_rmem sysctl accepts a value that makes tcp_full_space truncate to zero; tcp_rcvbuf_grow then divides by the zero receive-space value during buffer growth. The crash requires an unusually small, locally configured tcp_rmem value and a TCP connection that reaches receive-buffer growth.

The record

CVE
CVE-2026-98299
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1c4bb940c3bb4325bb88ac1b7eaf5faaa39e7d63
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <60df201dbb19a1bf6478b56d100f7ae1fe90e46a
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <67b83c15bed9eeeb8d1a6dbf88a5f79525970173
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7898bda1ebc198f5559b301a96dd5398edd4d4d3
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <83a945a529d6e002dd7339c532288a931f463dba
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <879907631b9e70eedb62d76461b29afa106ebe7a
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8e32532d0fa3191ecf9524b0e6bafa0832e712ba
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9a4f49bf8d2da4e52e904f60c29cca317bab9b3a
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1c4bb940c3bb4325bb88ac1b7eaf5faaa39e7d63; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <60df201dbb19a1bf6478b56d100f7ae1fe90e46a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <67b83c15bed9eeeb8d1a6dbf88a5f79525970173; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7898bda1ebc198f5559b301a96dd5398edd4d4d3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <83a945a529d6e002dd7339c532288a931f463dba; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <879907631b9e70eedb62d76461b29afa106ebe7a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8e32532d0fa3191ecf9524b0e6bafa0832e712ba; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9a4f49bf8d2da4e52e904f60c29cca317bab9b3a; version=2.6.12

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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