CVE-2026-63955

Last refreshed2026-10-30

Status: UPDATED | Advisory ID: CVE-2026-63955

Key Details

CVE	CVE-2026-63955
CVSS Score / Version	7.5 (High) / CVSS v3.1
Updated	2026-10-30
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.
Affected products	Linux Kernel

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

mm/vmalloc: do not trigger BUG() on BH disabled context

__get_vm_area_node() currently triggers a BUG() if in_interrupt() returns

true. However, in_interrupt() also reports true when BH are disabled.

The bridge code can call rhashtable_lookup_insert_fast() with bottom

halves disabled:

__vlan_add()

-> br_fdb_add_local()

spin_lock_bh(&br->hash_lock); <-- Disable BH

-> fdb_add_local()

-> fdb_create()

-> rhashtable_lookup_insert_fast()

-> kvmalloc()

-> vmalloc()

-> __get_vm_area_node()

-> BUG_ON(in_interrupt())

spin_unlock_bh(&br->hash_lock)

this triggers the BUG() despite the caller not being in NMI or

hard IRQ context.

Replace the in_interrupt() check with in_nmi() || in_hardirq(). (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-63955
CVE	https://www.cve.org/CVERecord?id=CVE-2026-63955

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-63955

CVE

https://www.cve.org/CVERecord?id=CVE-2026-63955