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Fencer Vulns
medium 5.5

CVE-2021-28950 json

An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8.

published 2021-03-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15601

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8. A "stall on CPU" can occur because a retry loop continually finds the same bad inode, aka CID-775c5033a0d1.

Patch / fix

  • linux linux_kernel 5.11.8
  • linux Debian 14, Debian 13, Debian 12 5.10.24-1

debian advisories DEBIAN-CVE-2021-28950

  • linux Ubuntu 20.04 LTS 5.4.0-74.83
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1049.51
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1044.47
  • linux-gke Ubuntu 20.04 LTS 5.4.0-1044.46
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1040.41
  • linux-azure Ubuntu 20.04 LTS 5.4.0-1048.50
  • linux-gkeop Ubuntu 20.04 LTS 5.4.0-1016.17
  • linux-raspi Ubuntu 20.04 LTS 5.4.0-1036.39

ubuntu advisories UBUNTU-CVE-2021-28950

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

  • kernel RHEL 8 4.18.0-348.el8
  • perf RHEL 8 4.18.0-348.el8
  • bpftool RHEL 8 4.18.0-348.el8
  • kernel-core RHEL 8 4.18.0-348.el8
  • kernel-tools RHEL 8 4.18.0-348.el8
  • python3-perf RHEL 8 4.18.0-348.el8
  • kernel-modules RHEL 8 4.18.0-348.el8
  • kernel-zfcpdump RHEL 8 4.18.0-348.el8

red hat advisories RHSA-2021:4356RHSA-2021:4140RHSA-2021:4648RHSA-2021:4650

  • kernel-64kb SLE Module for Basesystem 15 SP3 5.3.18-59.5.2
  • kernel-syms SLE Module for Development Tools 15 SP3 5.3.18-59.5.1
  • kernel-source SLE Module for Development Tools 15 SP3, SLE Module for Basesystem 15 SP3 5.3.18-59.5.2
  • kernel-default SLE Workstation Extension 15 SP3, SLE Module for Legacy 15 SP3, SLE Module for Basesystem 15 SP3 +2 more 5.3.18-59.5.2
  • kernel-preempt SLE Workstation Extension 15 SP3, SLE Module for Development Tools 15 SP3, SLE Module for Basesystem 15 SP3 5.3.18-59.5.2
  • kernel-zfcpdump SLE Module for Basesystem 15 SP3 5.3.18-59.5.2
  • kernel-obs-build SLE Module for Development Tools 15 SP3 5.3.18-59.5.1
  • kernel-default-base SLE Module for Basesystem 15 SP3 5.3.18-59.5.2.18.2.2

suse advisories SUSE-SU-2021:1977-1SUSE-SU-2021:1975-1SUSE-SU-2021:1625-1SUSE-SU-2021:1624-1SUSE-SU-2021:1623-1SUSE-SU-2021:1617-1

  • kernel-64kb openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-syms openSUSE Leap 15.3 5.3.18-59.5.1
  • kernel-obs-qa openSUSE Leap 15.3 5.3.18-59.5.1
  • kernel-source openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-default openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-preempt openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-kvmsmall openSUSE Leap 15.3 5.3.18-59.5.2
  • kernel-zfcpdump openSUSE Leap 15.3 5.3.18-59.5.2

opensuse advisories openSUSE-SU-2021:1977-1openSUSE-SU-2021:1975-1openSUSE-SU-2021:0758-1openSUSE-SU-2021:0579-1

  • kernel CBL-Mariner 2.0 5.10.78.1-1

azure linux advisories AZL-6538

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

  • linux Arch Linux 5.11.8.arch1-1
  • linux-hardened Arch Linux 5.11.8.hardened1-1
  • linux-zen Arch Linux 5.11.8.zen1-1
  • linux-lts Arch Linux 5.10.25-1

arch linux advisories AVG-1711AVG-1712AVG-1713AVG-1714

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-2021-28950 updated cvss 5.5

kernel: fuse: stall on CPU can occur because a retry loop continually finds the same bad inode

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-348.el8, kernel-debuginfo-common-aarch64 4.18.0-348.el8, kernel-debuginfo-common-ppc64le 4.18.0-348.el8 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-348.el8, kernel 4.18.0-348.el8, bpftool 4.18.0-348.el8, kernel-core 4.18.0-348.el8, kernel-tools 4.18.0-348.el8, python3-perf 4.18.0-348.el8, +15 more
    fixed: vendor fix RHSA-2021:4356
  • Red Hat Enterprise Linux BaseOS EUS (v.8.4) perf 4.18.0-305.28.1.el8_4, kernel 4.18.0-305.28.1.el8_4, bpftool 4.18.0-305.28.1.el8_4, kernel-core 4.18.0-305.28.1.el8_4, kernel-tools 4.18.0-305.28.1.el8_4, python3-perf 4.18.0-305.28.1.el8_4, +15 more Red Hat Enterprise Linux CRB EUS (v.8.4) kernel-debuginfo-common-x86_64 4.18.0-305.28.1.el8_4, kernel-debuginfo-common-aarch64 4.18.0-305.28.1.el8_4, kernel-debuginfo-common-ppc64le 4.18.0-305.28.1.el8_4
    fixed: vendor fix RHSA-2021:4650
  • Red Hat Enterprise Linux NFV EUS (v.8.4) kernel-rt 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-kvm 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-core 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-modules 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-debug-kvm 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-debug-core 4.18.0-305.28.1.rt7.100.el8_4, +4 more
    fixed: vendor fix RHSA-2021:4648
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-348.rt7.130.el8, kernel-rt-core 4.18.0-348.rt7.130.el8, kernel-rt-modules 4.18.0-348.rt7.130.el8, kernel-rt-debug-core 4.18.0-348.rt7.130.el8, kernel-rt-debug-modules 4.18.0-348.rt7.130.el8, kernel-rt-modules-extra 4.18.0-348.rt7.130.el8, +2 more Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-348.rt7.130.el8, kernel-rt-kvm 4.18.0-348.rt7.130.el8, kernel-rt-core 4.18.0-348.rt7.130.el8, kernel-rt-modules 4.18.0-348.rt7.130.el8, kernel-rt-debug-kvm 4.18.0-348.rt7.130.el8, kernel-rt-debug-core 4.18.0-348.rt7.130.el8, +4 more
    fixed: vendor fix RHSA-2021:4140
  • Red Hat Enterprise Linux RT EUS (v.8.4) kernel-rt 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-core 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-modules 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-debug-core 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-debug-modules 4.18.0-305.28.1.rt7.100.el8_4, kernel-rt-modules-extra 4.18.0-305.28.1.rt7.100.el8_4, +2 more
    fixed: vendor fix RHSA-2021:4648
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    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

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/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
Technology feeds

References

Sources

Fencer Vulns 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.