csirt@kutim:~/threat-intel/cve/CVE-2026-64009

Katalog CVE

CVSS 7.8 · High EPSS 0,20%

Kerentanan Out-of-bounds Write pada linux kernel. Skor CVSS 3.1 7.8 (High) menurut CNA.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: xfrm: Check for underflow in xfrm_state_mtu Leo Lin reported OOB write issue in esp component: xfrm_state_mtu() returns u32 but performs its arithmetic in unsigned modulo-2^32 space using an attacker-influenced "header_len + authsize + net_adj" subtracted from a small "mtu" argument. A nobody user can install an IPv4 ESP tunnel SA with a large authentication key (XFRMA_ALG_AUTH_TRUNC, e.g. hmac(sha512), 64-byte key, 64-byte trunc), configure a small interface MTU (68 bytes), and set XFRMA_TFCPAD to a large value. When a single UDP datagram is then sent through the tunnel, xfrm_state_mtu() underflows to a near-2^32 value, and esp_output() consumes it as a signed int via: padto = min(x->tfcpad, xfrm_state_mtu(x, mtu_cached)) esp.tfclen = padto - skb->len (assigned to int) esp.tfclen ends up negative (e.g. -207). It is sign-extended to size_t when passed to memset() inside esp_output_fill_trailer(), producing a ~16 EB write of zeroes at skb_tail_pointer(skb). KASAN logs it as "Write of size 18446744073709551537 at addr ffff888...". Check for underflow and return 1. This causes the sendmsg attempt to fail with ENETUNREACH.

Rincian

Terbit di NVD
19 Juli 2026
Terakhir diubah
13 Oktober 2026
Status NVD
Analyzed
CVSS 3.1
7.8 (High), sumber CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-787: Out-of-bounds Write
EPSS (30 hari)
0,20% peluang dieksploitasi; lebih tinggi dari 9,2% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
linux linux kernel Versi 2.6.22 hingga sebelum 5.10.259
linux linux kernel Versi 5.11 hingga sebelum 5.15.210
linux linux kernel Versi 5.16 hingga sebelum 6.1.176
linux linux kernel Versi 6.2 hingga sebelum 6.6.143
linux linux kernel Versi 6.7 hingga sebelum 6.12.93
linux linux kernel Versi 6.13 hingga sebelum 6.18.35
linux linux kernel Versi 6.19 hingga sebelum 7.0.12
linux linux kernel Versi 7.1 rc1
linux linux kernel Versi 7.1 rc2
linux linux kernel Versi 7.1 rc3
linux linux kernel Versi 7.1 rc4
linux linux kernel Versi 7.1 rc5

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 14 Okt 2026, 00:25 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.