CVE-2022-48991

Host memory disclosure via missing MMU notifications

Published Oct 21, 2024 · Updated Aug 5, 2026

Use-after-free in Linux khugepaged allows local users or guest OS users to read freed host page contents through KVM. The shmem and file collapse paths remove page-table entries without notifying secondary MMUs, which retain mappings without owning page references. Exploitation requires unprivileged local KVM access or control of a guest's shmem/file-backed memory; continued access can expose freed host data and corrupt reused pages.

CVSS severity8.8
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 khugepaged allows local users or guest OS users to read freed host page contents through KVM. The shmem and file collapse paths remove page-table entries without notifying secondary MMUs, which retain mappings without owning page references. Exploitation requires unprivileged local KVM access or control of a guest's shmem/file-backed memory; continued access can expose freed host data and corrupt reused pages.

The record

CVE
CVE-2022-48991
Published
Oct 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=4.8
  2. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <1a3f8c6cd29d9078cc81b29d39d0e9ae1d6a03c3
  3. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <275c626c131cfe141beeb6c575e31fa53d32da19
  4. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <5450535901d89a5dcca5fbbc59a24fe89caeb465
  5. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <5ffc2a75534d9d74d49760f983f8eb675fa63d69
  6. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <7f445ca2e0e59c7971d0b7b853465e50844ab596
  7. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <c23105673228c349739e958fa33955ed8faddcaf
  8. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <f268f6cf875f3220afc77bdd0bf1bb136eb54db9
  9. Affected versionversion=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <ff2a1a6f869650aec99e9d070b5ab625bfbc5bc3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.8; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <1a3f8c6cd29d9078cc81b29d39d0e9ae1d6a03c3; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <275c626c131cfe141beeb6c575e31fa53d32da19; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <5450535901d89a5dcca5fbbc59a24fe89caeb465; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <5ffc2a75534d9d74d49760f983f8eb675fa63d69; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <7f445ca2e0e59c7971d0b7b853465e50844ab596; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <c23105673228c349739e958fa33955ed8faddcaf; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <f268f6cf875f3220afc77bdd0bf1bb136eb54db9; version=f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 <ff2a1a6f869650aec99e9d070b5ab625bfbc5bc3

Published CVSS scores

8.8Linux kernel security teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
7.8CanonicalCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Amazon LinuxCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

No sourced classifications are available.

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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