9.1
CRITICAL CVSS 3.1
CVE-2026-101307
Remotely triggerable buffer overflow in tcp_rack
Description

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.

INFO

Published Date :

Oct. 15, 2026, 7:17 a.m.

Last Modified :

Oct. 20, 2026, 12:21 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-101307 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Freebsd freebsd
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Address heap buffer overflow vulnerability by updating the RACK stack.
  • Update the RACK stack to the latest version.
  • Apply any relevant security patches.
  • Review memory allocation logic.
  • Test the fix thoroughly.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-101307.

URL Resource
https://security.freebsd.org/advisories/FreeBSD-SA-26:70.tcp.asc Mitigation Patch Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-101307 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-101307 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-101307 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-101307 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Oct. 20, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
    Added CPE Configuration OR *cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p3:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p4:*:*:*:*:*:*
    Added Reference Type FreeBSD: https://security.freebsd.org/advisories/FreeBSD-SA-26:70.tcp.asc Types: Mitigation, Patch, Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 15, 2026

    Action Type Old Value New Value
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Removed CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 15, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added SSVC {'id': 'CVE-2026-101307', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-15T15:31:46.531780Z'}
  • New CVE Received by [email protected]

    Oct. 15, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CWE CWE-787
    Added CWE CWE-122
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/101xxx/CVE-2026-101307.json">CVE-2026-101307</a>
    Added Reference https://security.freebsd.org/advisories/FreeBSD-SA-26:70.tcp.asc
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.