Description
In the Linux kernel, the following vulnerability has been resolved:

scsi: target: core: Fix integer overflow in UNMAP bounds check

sbc_execute_unmap() checks LBA + range does not exceed the device capacity,
but does not guard against LBA + range wrapping around on 64-bit overflow.

Add an overflow check matching the pattern already used for WRITE_SAME in
the same file.
Published: 2026-06-24
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability originates from an integer overflow in the sbc_execute_unmap function within the Linux kernel's SCSI target core. When a UNMAP command is processed, the function adds the logical block address (LBA) to the requested range without guarding against a 64‑bit overflow, allowing the sum to wrap around. This bypasses the bounds check that ensures the operation does not exceed the device capacity, potentially leading to kernel memory corruption and a system crash. The CVE description confirms the addition of an overflow guard as the fix, indicating that prior to the patch, this overflow was exploitable. This flaw could result in a denial of service by crashing the kernel.

Affected Systems

Any Linux kernel version that does not contain the patch commit adding the overflow guard is affected. The defect exists in the generic SCSI target core module, so all distributions or custom builds that install the vulnerable kernel and provide SCSI UNMAP support are at risk. Versions from the earliest stable releases up to the commit date are vulnerable.

Risk and Exploitability

The CVSS score is 5.5, a moderate severity level that reflects the DoS potential. The EPSS score of < 1 % indicates a low likelihood of exploitation in the wild. The vulnerability is not listed in CISA's KEV catalog. Exploitation requires the attacker to have the ability to send crafted UNMAP requests to a target device, which typically requires local or privileged access to the SCSI subsystem. No public exploitation has been documented, so the threat remains theoretical pending successful memory corruption.

Generated by OpenCVE AI on August 13, 2026 at 19:25 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the Linux kernel to a release that includes the commit adding the integer overflow guard in sbc_execute_unmap.
  • If an immediate kernel update is not feasible, disable or reject UNMAP commands in the SCSI target configuration to avoid the vulnerable code path.
  • Restrict access to the SCSI target to privileged or trusted users only, minimizing the chance that an unprivileged attacker can send crafted UNMAP requests.

Generated by OpenCVE AI on August 13, 2026 at 19:25 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Debian DLA Debian DLA DLA-4664-1 linux security update
Debian DLA Debian DLA DLA-4665-1 linux security update
Debian DLA Debian DLA DLA-4671-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-8566-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8567-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8568-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8569-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-1 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-8596-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-2 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8603-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8606-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8607-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8608-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8609-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8610-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8574-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8595-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8618-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8619-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-3 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-4 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8663-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8664-1 Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8665-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8668-1 Linux kernel (GCP) vulnerabilities
History

Sat, 27 Jun 2026 02:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-680

Sat, 27 Jun 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-190
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Wed, 24 Jun 2026 23:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-680

Wed, 24 Jun 2026 17:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: scsi: target: core: Fix integer overflow in UNMAP bounds check sbc_execute_unmap() checks LBA + range does not exceed the device capacity, but does not guard against LBA + range wrapping around on 64-bit overflow. Add an overflow check matching the pattern already used for WRITE_SAME in the same file.
Title scsi: target: core: Fix integer overflow in UNMAP bounds check
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-24T16:29:30.671Z

Reserved: 2026-06-09T07:44:35.379Z

Link: CVE-2026-53021

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-06-24T17:17:13.410

Modified: 2026-07-15T14:12:03.090

Link: CVE-2026-53021

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-06-24T00:00:00Z

Links: CVE-2026-53021 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-13T19:30:03Z

Weaknesses
  • CWE-190

    Integer Overflow or Wraparound