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Fencer Intel
medium 5.5

CVE-2015-8952 json

The mbcache feature in the ext2 and ext4 filesystem implementations in the Linux kernel before 4.6 mishandles xattr block caching, which al…

published 2016-10-16 10 y ago modified 2026-06-17 4 mo ago also EUVD-2015-8808

cvss
5.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

The mbcache feature in the ext2 and ext4 filesystem implementations in the Linux kernel before 4.6 mishandles xattr block caching, which allows local users to cause a denial of service (soft lockup) via filesystem operations in environments that use many attributes, as demonstrated by Ceph and Samba.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 4.6.1-1

debian advisories DEBIAN-CVE-2015-8952

  • linux Ubuntu 16.04 LTS 4.4.0-116.140
  • linux-aws Ubuntu 14.04 LTS 4.4.0-1014.14
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1052.61
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1019.24
  • linux-raspi2 Ubuntu 16.04 LTS 4.4.0-1085.93
  • linux-lts-xenial Ubuntu 14.04 LTS 4.4.0-116.140~14.04.1
  • linux-snapdragon Ubuntu 16.04 LTS 4.4.0-1087.92
  • linux-snapdragon Ubuntu 18.04 LTS 4.15.0-1053.57

ubuntu advisories UBUNTU-CVE-2015-8952

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-8952 updated cvss 5.5

kernel: mbcache code subject to softlockup DOS in cache management

  • Red Hat Enterprise Linux 5 kernel
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 5.5 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-19 Data Processing Errors
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.