CVE-2026-89653

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.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-25)

Published

2026-09-11

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

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

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