SB2026102382 - Race condition in Linux kernel ipv4

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Main Vulnerability Database SB2026102382

SB2026102382 - Race condition in Linux kernel ipv4

Published: October 23, 2026

Security Bulletin ID SB2026102382
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Race condition (CVE-ID: CVE-2026-99071)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local privileged user to trigger a spurious kernel warning.

The vulnerability exists due to a race condition in fib_alias_hw_flags_set() when sizing and populating asynchronous IPv4 route notifications using independent snapshots protected only by RCU. A local privileged user can trigger concurrent route updates to cause a spurious kernel warning if nexthop group replacement increases the notification size between these snapshots and fib_dump_info() returns -EMSGSIZE.

The race requires nexthop compatibility mode to be enabled.


Remediation

Install update from vendor's website.

References