CVE-2023-1583

System crash via stale io_uring allocation metadata

Published Mar 24, 2023 · Updated Feb 20, 2025

NULL pointer dereference in Linux Kernel 5.19 through 6.3 allows local users to crash the system through io_uring file registration. Fixed-file teardown leaves file_alloc_end and alloc_hint uncleared, so later IORING_FILE_INDEX_ALLOC processing searches a freed NULL bitmap. Local unprivileged access and io_uring availability are required; successful triggering causes a kernel crash without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Linux Kernel 5.19 through 6.3 allows local users to crash the system through io_uring file registration. Fixed-file teardown leaves file_alloc_end and alloc_hint uncleared, so later IORING_FILE_INDEX_ALLOC processing searches a freed NULL bitmap. Local unprivileged access and io_uring availability are required; successful triggering causes a kernel crash without reported data disclosure or modification.

The record

CVE
CVE-2023-1583
Published
Mar 24, 2023
Updated
Feb 20, 2025
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 20, 2025Record 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=affected kernel 5.19, 6.0, 6.1, 6.2, 6.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=affected kernel 5.19, 6.0, 6.1, 6.2, 6.3

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS: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.

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

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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