CVE-2021-47058

Local kernel memory corruption via dangling debugfs name

Published Feb 29, 2024 · Updated May 23, 2026

Use-after-free in Linux kernel regmap debugfs allows local users to corrupt kernel memory during regmap cache reinitialization. regmap_debugfs_exit() frees debugfs_name but leaves the pointer non-NULL, so regmap_debugfs_init() skips allocation and reuses the dangling name pointer. Triggering the regmap_reinit_cache() exit-and-init sequence requires local low-privileged access; successful exploitation can read or alter kernel data or crash the system.

CVSS severity7.8
High
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

Use-after-free in Linux kernel regmap debugfs allows local users to corrupt kernel memory during regmap cache reinitialization. regmap_debugfs_exit() frees debugfs_name but leaves the pointer non-NULL, so regmap_debugfs_init() skips allocation and reuses the dangling name pointer. Triggering the regmap_reinit_cache() exit-and-init sequence requires local low-privileged access; successful exploitation can read or alter kernel data or crash the system.

The record

CVE
CVE-2021-47058
Published
Feb 29, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 29, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=4.19.168 <4.19.191
  2. Affected versionversion=480c5e9c7e4c76c01d5f1f7b73832d7b77e6b427 <d8897f7b2283a500666c85ef06e820df38ed7b52
  3. Affected versionversion=5.10.8 <5.10.37
  4. Affected versionversion=5.11
  5. Affected versionversion=5.4.90 <5.4.119
  6. Affected versionversion=5b654b03007917f3f1015b2a5c288c1ea6ae8f65 <2dc1554d5f0fdaf47cc5bea442b84b9226fea867
  7. Affected versionversion=c9698380b01aed3281160d3ab25749b57d6913b8 <eb949f891226c012138ffd9df90d1e509f428ae6
  8. Affected versionversion=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <b9e569ae1da3a113b3acee8703c94777fd20938a
  9. Affected versionversion=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <c764e375ae647832de1ee73d43a4bb3ef8a8f43d
  10. Affected versionversion=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <e41a962f82e7afb5b1ee644f48ad0b3aee656268

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.19.168 <4.19.191; version=480c5e9c7e4c76c01d5f1f7b73832d7b77e6b427 <d8897f7b2283a500666c85ef06e820df38ed7b52; version=5.10.8 <5.10.37; version=5.11; version=5.4.90 <5.4.119; version=5b654b03007917f3f1015b2a5c288c1ea6ae8f65 <2dc1554d5f0fdaf47cc5bea442b84b9226fea867; version=c9698380b01aed3281160d3ab25749b57d6913b8 <eb949f891226c012138ffd9df90d1e509f428ae6; version=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <b9e569ae1da3a113b3acee8703c94777fd20938a; version=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <c764e375ae647832de1ee73d43a4bb3ef8a8f43d; version=cffa4b2122f5f3e53cf3d529bbc74651f95856d5 <e41a962f82e7afb5b1ee644f48ad0b3aee656268

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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