CVE-2021-47595Public exploit

Host crash via idle ETS class removal

Published Jun 19, 2024 · Updated May 11, 2026

Denial of service in Linux kernel 5.10.83 through 5.10.87 and 5.15.6 through 5.15.10 allows local users to crash the host. ets_qdisc_change removes a DRR class from the active list while reducing ETS bands even when the idle class was never linked, corrupting the kernel list. A local user able to reconfigure an ETS qdisc can trigger a kernel BUG and panic, interrupting the host service.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel 5.10.83 through 5.10.87 and 5.15.6 through 5.15.10 allows local users to crash the host. ets_qdisc_change removes a DRR class from the active list while reducing ETS bands even when the idle class was never linked, corrupting the kernel list. A local user able to reconfigure an ETS qdisc can trigger a kernel BUG and panic, interrupting the host service.

The record

CVE
CVE-2021-47595
Published
Jun 19, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 19, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.10.83 <5.10.88
  2. Affected versionversion=5.15.6 <5.15.11
  3. Affected versionversion=ae2659d2c670252759ee9c823c4e039c0e05a6f2 <81fbdd45652d8605a029e78ef14a6aaa529c4e72
  4. Affected versionversion=de6d25924c2a8c2988c6a385990cafbe742061bf <c062f2a0b04d86c5b8c9d973bea43493eaca3d32
  5. Affected versionversion=e25bdbc7e951ae5728fee1f4c09485df113d013c <491c1253441e2fdc8f6a6f4976e3f13440419b7a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10.83 <5.10.88; version=5.15.6 <5.15.11; version=ae2659d2c670252759ee9c823c4e039c0e05a6f2 <81fbdd45652d8605a029e78ef14a6aaa529c4e72; version=de6d25924c2a8c2988c6a385990cafbe742061bf <c062f2a0b04d86c5b8c9d973bea43493eaca3d32; version=e25bdbc7e951ae5728fee1f4c09485df113d013c <491c1253441e2fdc8f6a6f4976e3f13440419b7a

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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