CVE-2025-21738MediumMicrosoft CVSS 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Microsoft security update for CVE-2025-21738 — cbl2 kernel

Published
June 3, 2026
Last Modified
—

🔗 CVE IDs covered (1)

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21738. This page also shows what EchelonGraph holds for CVE-2025-21738, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products5

  • cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0
  • cbl2 kernel 5.15.200.1-1 on CBL Mariner 2.0
  • cbl2 kernel 5.15.202.1-1
  • cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0
  • cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0

✅ Updates Microsoft lists: 1 update

1 row: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.

KB articleUpdateFixed build
—Security Update—

🧭 EchelonGraph on CVE-2025-21738

EchelonGraph score
5.5 MEDIUM
CISA KEV
Not listed
Fix status
A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

In the Linux kernel, the following vulnerability has been resolved: ata: libata-sff: Ensure that we cannot write outside the allocated buffer reveliofuzzing reported that a SCSI_IOCTL_SEND_COMMAND ioctl with out_len set to 0xd42, SCSI command set to ATA_16 PASS-THROUGH, ATA command set to ATA_NOP, and protocol set to ATA_PROT_PIO, can cause ata_pio_sector() to write outside the allocated buffer, overwriting random memory. While a ATA device is supposed to abort a ATA_NOP command, there does seem to be a bug either in libata-sff or QEMU, where either this status is not set, or the status is cleared before read by ata_sff_hsm_move(). Anyway, that is most likely a separate bug. Looking at __atapi_pio_bytes(), it already has a safety check to ensure that __atapi_pio_bytes() cannot write outside the allocated buffer. Add a similar check to ata_pio_sector(), such that also ata_pio_sector() cannot write outside the allocated buffer.

Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-21738, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (2)