CVE-2021-47373

Service interruption via off-by-one VPE cleanup

Published May 21, 2024 · Updated May 11, 2026

Resource leak in the Linux kernel 4.14 through 5.15-rc2 allows local users to exhaust VPE resources during GICv3 ITS allocation errors. The its_vpe_irq_domain_alloc error path calculates one too few initialized VPEs for cleanup when its_vpe_init fails, leaving one VPE allocated. Exploitation requires local low-privilege access and the affected GICv3 ITS virtualization path; repeated failures can exhaust resources and interrupt service.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource leak in the Linux kernel 4.14 through 5.15-rc2 allows local users to exhaust VPE resources during GICv3 ITS allocation errors. The its_vpe_irq_domain_alloc error path calculates one too few initialized VPEs for cleanup when its_vpe_init fails, leaving one VPE allocated. Exploitation requires local low-privilege access and the affected GICv3 ITS virtualization path; repeated failures can exhaust resources and interrupt service.

The record

CVE
CVE-2021-47373
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-193, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=4.14
  2. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <280bef512933b2dda01d681d8cbe499b98fc5bdd
  3. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <42d3711c23781045e7a5cd28536c774b9a66d20b
  4. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <568662e37f927e3dc3e475f3ff7cf4ab7719c5e7
  5. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <5701e8bff314c155e7afdc467b1e0389d86853d0
  6. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <7d39992d45acd6f2d6b2f62389c55b61fb3d486b
  7. Affected versionversion=7d75bbb4bc1ad90386776459d37e4ddfe605671e <e0c1c2e5da19685a20557a50f10c6aa4fa26aa84

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <280bef512933b2dda01d681d8cbe499b98fc5bdd; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <42d3711c23781045e7a5cd28536c774b9a66d20b; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <568662e37f927e3dc3e475f3ff7cf4ab7719c5e7; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <5701e8bff314c155e7afdc467b1e0389d86853d0; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <7d39992d45acd6f2d6b2f62389c55b61fb3d486b; version=7d75bbb4bc1ad90386776459d37e4ddfe605671e <e0c1c2e5da19685a20557a50f10c6aa4fa26aa84

Published CVSS scores

5.5NIST NVDCVSS: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
4.4OracleCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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