---
id: CVE-2026-101307
title: >-
  When the PCM sample array needs to grow, the RACK stack doubles a 16-bit
  allocation counter
summary: >-
  When the PCM sample array needs to grow, the RACK stack doubles a 16-bit
  allocation counter.  Repeated doublings caused the counter to wrap to zero,
  resulting in a near-zero-length allocation followed by a copy of the existing
  samples in…
severity: high
cvss: 8.2
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-122
  - CWE-787
vendor: FreeBSD
product: FreeBSD
affected:
  - FreeBSD >= 15.1-RELEASE < p5
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T17:17:08.527'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101307'
references:
  - url: 'https://security.freebsd.org/advisories/FreeBSD-SA-26:70.tcp.asc'
    label: secteam@freebsd.org
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T15:31:46.531780Z'
cvssSource: adp
ingestedAt: '2026-10-15T07:57:27.844Z'
epss: 0.00313
epssPercentile: 0.24085
---

## Overview

When the PCM sample array needs to grow, the RACK stack doubles a 16-bit allocation counter.  Repeated doublings caused the counter to wrap to zero, resulting in a near-zero-length allocation followed by a copy of the existing samples into the undersized buffer.  A remote peer can trigger the expansion by sending a sufficient number of ACKs on an established connection.

A remote attacker who can establish a TCP connection to a system using the RACK stack can trigger an out-of-bounds write of approximately 512 KB in the kernel heap possibly resulting in a kernel panic.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.