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Vulnerabilities

Vulnerability · CVE-2026-64422

net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes

Published Jul 25, 2026 · catalog updated Oct 15, 2026 · Linux Linux

Check if you run it

No confirmed exploitation is on record for CVE-2026-64422. EPSS is 0.14%. Act only if a listed version of Linux Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.14%
Remediation
Advisory link
Affected products
cpe linux/linux kernel · vendor Linux Linux

In the Linux kernel, the following vulnerability has been resolved: net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes Reject invalid values before they reach TCP socket state. The sysctl is stored as an but copied into the field for new sockets, so negative writes wrap to large values. With , the wrapped value can overflow the size calculation and drive the MTU probing path into an out-of-bounds read. Route writes through and require it to be at least 1. Also require to be at least 1 so the configured maximum cannot become negative either. When registering the table for a non-init network namespace, relocate pointers that refer into so the upper bound follows that namespace's . Harden itself by computing as . This keeps the send queue and window checks from being bypassed through signed integer overflow.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel2.6.24
  • vendor Linux Linuxversion unspecified

How to fix CVE-2026-64422

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-64422. EPSS is 0.14%. Act only if a listed version of Linux Linux is installed.

Which versions are affected?

Compare what you have installed with linux/linux kernel 2.6.24. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-190: Integer Overflow. EPSS 0.14%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 25, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes Reject invalid values before they reach TCP socket state. The sysctl is stored as an but copied into the field for new sockets, so negative writes wrap to large values. With , the wrapped value can overflow the size calculation and drive the MTU probing path into an

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes Reject invalid values before they reach TCP socket state. The sysctl is stored as an but copied into the field for new sockets, so negative writes wrap to large values. With , the wrapped value can overflow the size calculation and drive the MTU probing path into an

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-2026-64422

    In the Linux kernel, the following vulnerability has been resolved: net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes Reject invalid values before they reach TCP socket state. The sysctl is stored as an but copied into the field for new sockets, so negative writes

    vulnerability.circl.lu
  • CVE.orgVulnerability recordCVE-2026-64422

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-64422

    30-day exploitation probability 0.1%

    first.org
  • NIST NVDVulnerability recordCVE-2026-64422

    In the Linux kernel, the following vulnerability has been resolved: net: ipv4: bound TCP reordering sysctl writes and MTU probe sizes Reject invalid values before they reach TCP socket state. The sysctl is stored as an but copied into the `

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.