CVE-2023-53820

Kernel alarm via retained invalid loop offsets

Published Dec 9, 2025 · Updated May 23, 2026

An overflow-handling flaw in Linux kernel loop devices allows local users to retain invalid offsets after a rejected configuration ioctl. loop_set_status_from_info() assigns lo_offset and lo_sizelimit before validating overflow, then returns an error without restoring their prior values. Subsequent file-backed I/O consumes the invalid offset and triggers a kernel alarm; exploitation requires access to configure a loop device.

CVSS severityUnavailable
Unscored
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An overflow-handling flaw in Linux kernel loop devices allows local users to retain invalid offsets after a rejected configuration ioctl. loop_set_status_from_info() assigns lo_offset and lo_sizelimit before validating overflow, then returns an error without restoring their prior values. Subsequent file-backed I/O consumes the invalid offset and triggers a kernel alarm; exploitation requires access to configure a loop device.

The record

CVE
CVE-2023-53820
Published
Dec 9, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 9, 2025CVE 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

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=0455bef69028c65065f16bb04635591b2374249b <3e7d0968203d668af6036b9f9199c7b62c8a3581
  2. Affected versionversion=13b2856037a651ba3ab4a8b25ecab3e791926da3 <2ea7077748e5d7cc64f1c31342c802fe66ea7426
  3. Affected versionversion=18e28817cb516b39de6281f6db9b0618b2cc7b42
  4. Affected versionversion=2035c770bfdbcc82bd52e05871a7c82db9529e0f <6bdf4e6dfb60cbb6121ccf027d97ed2ec97c0bcb
  5. Affected versionversion=4.14.292 <4.15
  6. Affected versionversion=4.19.257 <4.19.312
  7. Affected versionversion=4.9.327 <4.10
  8. Affected versionversion=5.10.140 <5.10.173
  9. Affected versionversion=5.15.64 <5.15.100
  10. Affected versionversion=5.19.6 <5.20
  11. Affected versionversion=5.4.212 <5.4.274
  12. Affected versionversion=6.0
  13. Affected versionversion=6858933131d0dadac071c4d33335a9ea4b8e76cf <c79a924ed6afac1708dfd370ba66bcf6a852ced6
  14. Affected versionversion=9be7fa7ead18a48940df7b59d993bbc8b9055c15
  15. Affected versionversion=a217715338fd48f72114725aa7a40e484a781ca7 <832580af82ace363205039a8e7c4ef04552ccc1a
  16. Affected versionversion=adf0112d9b8acb03485624220b4934f69bf13369
  17. Affected versionversion=b40877b8562c5720d0a7fce20729f56b75a3dede <861021710bba9dfa0749a3c209a6c1773208b1f1
  18. Affected versionversion=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <258809bf22bf71d53247856f374f2b1d055f2fd4
  19. Affected versionversion=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <4be26d553a3f1d4f54f25353d1496c562002126d
  20. Affected versionversion=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=0455bef69028c65065f16bb04635591b2374249b <3e7d0968203d668af6036b9f9199c7b62c8a3581; version=13b2856037a651ba3ab4a8b25ecab3e791926da3 <2ea7077748e5d7cc64f1c31342c802fe66ea7426; version=18e28817cb516b39de6281f6db9b0618b2cc7b42; version=2035c770bfdbcc82bd52e05871a7c82db9529e0f <6bdf4e6dfb60cbb6121ccf027d97ed2ec97c0bcb; version=4.14.292 <4.15; version=4.19.257 <4.19.312; version=4.9.327 <4.10; version=5.10.140 <5.10.173; version=5.15.64 <5.15.100; version=5.19.6 <5.20; version=5.4.212 <5.4.274; version=6.0; version=6858933131d0dadac071c4d33335a9ea4b8e76cf <c79a924ed6afac1708dfd370ba66bcf6a852ced6; version=9be7fa7ead18a48940df7b59d993bbc8b9055c15; version=a217715338fd48f72114725aa7a40e484a781ca7 <832580af82ace363205039a8e7c4ef04552ccc1a; version=adf0112d9b8acb03485624220b4934f69bf13369; version=b40877b8562c5720d0a7fce20729f56b75a3dede <861021710bba9dfa0749a3c209a6c1773208b1f1; version=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <258809bf22bf71d53247856f374f2b1d055f2fd4; version=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <4be26d553a3f1d4f54f25353d1496c562002126d; version=c490a0b5a4f36da3918181a8acdc6991d967c5f3 <9f6ad5d533d1c71e51bdd06a5712c4fbc8768dfa

Published CVSS scores

No CVSS assessment is available in this record.

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
PrivilegesUnavailable
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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