Out-of-bounds Read in Linux

CVE-2026-52958

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in osdmap_decode() When decoding osd_state and osd_weight from an incoming osdmap in osdmap_decode(), both are decoded for each osd, i.e., map->max_osd times. The ceph_decode_need() check only accounts for sizeof(*map->osd_weight) once. This can potentially result in an out-of-bounds memory access if the incoming message is corrupted such that the max_osd value exceeds the actual content of the osdmap message. This patch fixes the issue by changing the corresponding part in the ceph_decode_need() check to account for map->max_osd*sizeof(*map->osd_weight).

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-52958: held from 0.005 to 0.007.

EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.002

Affected products

  • Linux — versions dcbc919a5dc8c2629684a113a90c0b6fe10c3462, 5.3, 0
  • Linux Kernel — versions 7.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-52958?
CVE-2026-52958 is a critical-severity vulnerability in Linux, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-06-24.
How severe is CVE-2026-52958?
Critical severity. CVSS v3 base score is 9.1 out of 10.