CVE-2026-89653

critical

Description

In the Linux kernel, the following vulnerability has been resolved: ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode MDSMap export_targets entries are monitor controlled. check_new_map() uses each entry as a bit number in a fixed stack bitmap, so a rank outside the protocol namespace can make set_bit() write past the end of the array. Reject ranks outside CEPH_MAX_MDS while decoding the map. Do not validate against possible_max_rank here because maps may legitimately reference ranks beyond a temporarily reduced max_mds.

References

https://git.kernel.org/stable/c/aedc9053d909508a5f56c3f49f885fc030df4730

https://git.kernel.org/stable/c/96c3f5fbb0d5386e7111426f047f98cec4586674

https://git.kernel.org/stable/c/736adee11af36e407ed902264f8b2fb5cf94b62f

https://git.kernel.org/stable/c/4d298880f82c42383b36946bafde7ccf4d804c9b

Details

Source: Mitre, NVD

Published: 2026-09-11

Updated: 2026-09-13

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00168