CVE-2026-4247

Katalog CVE

CVSS 7.5 · High EPSS 1,4%

Kerentanan Missing Release of Memory after Effective Lifetime pada freebsd. Skor CVSS 3.1 7.5 (High) menurut CISA ADP.

Deskripsi (NVD)

When a challenge ACK is to be sent tcp_respond() constructs and sends the challenge ACK and consumes the mbuf that is passed in. When no challenge ACK should be sent the function returns and leaks the mbuf. If an attacker is either on path with an established TCP connection, or can themselves establish a TCP connection, to an affected FreeBSD machine, they can easily craft and send packets which meet the challenge ACK criteria and cause the FreeBSD host to leak an mbuf for each crafted packet in excess of the configured rate limit settings i.e. with default settings, crafted packets in excess of the first 5 sent within a 1s period will leak an mbuf. Technically, off-path attackers can also exploit this problem by guessing the IP addresses, TCP port numbers and in some cases the sequence numbers of established connections and spoofing packets towards a FreeBSD machine, but this is harder to do effectively.

Rincian

Terbit di NVD

26 Maret 2026

Terakhir diubah

17 Juni 2026

Status NVD

Analyzed

CVSS 3.1

7.5 (High), sumber CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-401: Missing Release of Memory after Effective Lifetime

EPSS (30 hari)

1,4% peluang dieksploitasi; lebih tinggi dari 71,8% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://security.freebsd.org/advisories/FreeBSD-SA-26:06.tcp.asc advisory vendor