CVE-2026-46086

Katalog CVE

CVSS 5.5 · Medium EPSS 0,17%

Kerentanan NULL Pointer Dereference pada linux kernel. Skor CVSS 3.1 5.5 (Medium) menurut NVD.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: net: bridge: use a stable FDB dst snapshot in RCU readers Local FDB entries can be rewritten in place by `fdb_delete_local()`, which updates `f->dst` to another port or to `NULL` while keeping the entry alive. Several bridge RCU readers inspect `f->dst`, including `br_fdb_fillbuf()` through the `brforward_read()` sysfs path. These readers currently load `f->dst` multiple times and can therefore observe inconsistent values across the check and later dereference. In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change `f->dst` after the NULL check and before the `port_no` dereference, leading to a NULL-ptr-deref. Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each affected RCU reader and using that snapshot for the rest of the access sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()` with `WRITE_ONCE()` so the readers and writer use matching access patterns.

Rincian

Terbit di NVD

27 Mei 2026

Terakhir diubah

8 September 2026

Status NVD

Undergoing Analysis

CVSS 3.1

5.5 (Medium), sumber NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator

Jenis kelemahan (CWE)

CWE-476: NULL Pointer Dereference

EPSS (30 hari)

0,17% peluang dieksploitasi; lebih tinggi dari 5,4% CVE lain

Produk dan versi terdampak

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

• https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110 patch
• https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a patch
• https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5 patch
• https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef patch
• https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f patch
• https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e patch
• https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8 patch
• https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808 patch
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html