CVE-2026-53304

Soft lockup via unvalidated SCSI reserve size

Published Jun 26, 2026 · Updated Jun 26, 2026

Improper input validation in the Linux kernel SCSI generic driver allows local users with administrative privileges to cause a soft lockup. The sg driver's def_reserved_size module parameter accepts a negative value without the 0-to-1,048,576 validation applied by sg_proc_write_dressz, and sg_build_reserve then stalls while allocating the per-file reserve during sg_open. Writing the sysfs module parameter requires root-equivalent local access, and opening an sg device after the invalid write can monopolize a CPU in a soft lockup.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in the Linux kernel SCSI generic driver allows local users with administrative privileges to cause a soft lockup. The sg driver's def_reserved_size module parameter accepts a negative value without the 0-to-1,048,576 validation applied by sg_proc_write_dressz, and sg_build_reserve then stalls while allocating the per-file reserve during sg_open. Writing the sysfs module parameter requires root-equivalent local access, and opening an sg device after the invalid write can monopolize a CPU in a soft lockup.

The record

CVE
CVE-2026-53304
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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=2.6.19
  2. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <1afd963fcd963db0dc5d47df6dfcf010c9c4647e
  3. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <3d74e0654ac908c65a8f20373091826fe43b1363
  4. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202
  5. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <c47ccfb3d80dfed522ca06a5954ac97488d78c5a
  6. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <c5f4a211e82d04ccc1809311322c47023bbe66e2
  7. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <d06a310b45e153872033dd0cf19d5a2279121099
  8. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <fe671d3c84ffb1b763d590c25195755adeaadaba
  9. Affected versionversion=6460e75a104d10458817d2f5b2fbff775bf0b43a <feade299e932967de27519338d41de348fb5b061

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.19; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <1afd963fcd963db0dc5d47df6dfcf010c9c4647e; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <3d74e0654ac908c65a8f20373091826fe43b1363; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <9676ca7b1ef31a3a65b3e61e7ce3b54ce7364202; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <c47ccfb3d80dfed522ca06a5954ac97488d78c5a; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <c5f4a211e82d04ccc1809311322c47023bbe66e2; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <d06a310b45e153872033dd0cf19d5a2279121099; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <fe671d3c84ffb1b763d590c25195755adeaadaba; version=6460e75a104d10458817d2f5b2fbff775bf0b43a <feade299e932967de27519338d41de348fb5b061

Published CVSS scores

5.5NIST NVDCVSS: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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking
T1499.004Endpoint Denial of Service: Application 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo