PT-2026-28217 · Freebsd · Freebsd

Michael Tuexen · Published 2026-03-26 · Updated 2026-03-26 · CVE-2026-4247

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions FreeBSD (affected versions not specified)

Description A flaw exists where the tcp respond() function can leak an mbuf when a challenge ACK is not sent. An attacker on the network path, or able to establish a TCP connection, can craft packets to trigger this leak, exceeding the configured rate limit. Off-path attackers may also exploit this by spoofing packets, though this is more difficult. The issue involves leaking an mbuf for each crafted packet sent in excess of the rate limit settings.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Memory Leak

Weakness Enumeration

CWE-401

Related Identifiers

CVE-2026-4247

Affected Products

Freebsd

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-4247 · Security Note
• https://security.freebsd.org/advisories/FreeBSD-SA-26:06.tcp.asc · Vendor Advisory
• https://twitter.com/CVEnew/status/2037137729771733297 · Twitter Post
• https://freebsd.org/security/advisories/FreeBSD-SA-26:06.tcp.asc · Note