CVE-2026-89656

Last refreshed2026-10-17

Status: UPDATED | Advisory ID: CVE-2026-89656

Key Details

CVE	CVE-2026-89656
CVSS Score / Version	9.8 (Critical) / CVSS v3.1
Updated	2026-10-16
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 high; integrity impact is high; availability impact is high.
Affected products	Linux Kernel

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

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

libceph: reject buckets with mismatched CRUSH ids

crush_decode() stores bucket data by array slot, and the mapper later

derives the per-bucket workspace index from the decoded bucket id. A

malformed map can therefore make one bucket reuse another bucket's

workspace by encoding an id different from -1 - slot.

For uniform buckets, the second replica selection expands the source

bucket's permutation into that aliased workspace buffer. If the source

bucket is larger than the aliased bucket, the write runs past the smaller

permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN

reports a slab OOB write of 4 bytes in bucket_perm_choose().

Reject buckets whose encoded id does not match their array slot. Valid

CRUSH maps already use the canonical negative id corresponding to the

bucket slot, so this restores the invariant expected by

work->work[-1 - in->id] without changing valid map behavior. (NVD)

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

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-89656
CVE	https://www.cve.org/CVERecord?id=CVE-2026-89656

Source

Reference

NVD

CVE