CVE-2026-89653
Medium
Elevated severity or exploit probability.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.7%
52.6th percentile
CISA KEV
Not listed
Weakness / dates
—
Published 2026-09-11 · modified 2026-09-14
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/3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe
- https://git.kernel.org/stable/c/4d298880f82c42383b36946bafde7ccf4d804c9b
- https://git.kernel.org/stable/c/736adee11af36e407ed902264f8b2fb5cf94b62f
- https://git.kernel.org/stable/c/8c823bbab3c24e657469a84db96902ba82d4e8bb
- https://git.kernel.org/stable/c/96c3f5fbb0d5386e7111426f047f98cec4586674
- https://git.kernel.org/stable/c/aedc9053d909508a5f56c3f49f885fc030df4730
- https://git.kernel.org/stable/c/c4addccd05bacbef2144b4db14853d0308a218ac