CVE-2025-21846MediumMicrosoft 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-2025-21846

Published
July 11, 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-2025-21846. This page also shows what EchelonGraph holds for CVE-2025-21846, 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

  • azl3 kernel 6.6.78.1-3 on Azure Linux 3.0
  • azl3 kernel 6.6.82.1-1 on Azure Linux 3.0
  • cbl2 kernel 5.15.179.1-1 on CBL Mariner 2.0
  • cbl2 kernel 5.15.182.1-1 on CBL Mariner 2.0
  • cbl2 kernel 5.15.182.1-1 on CBL-Mariner 2.0

✅ Updates Microsoft lists: 3 updates

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

KB articleUpdateFixed build
—Security Update6.6.82.1-1
—Security Update—
—Security Update5.15.179.1-1

🧭 EchelonGraph on CVE-2025-21846

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: acct: perform last write from workqueue In [1] it was reported that the acct(2) system call can be used to trigger NULL deref in cases where it is set to write to a file that triggers an internal lookup. This can e.g., happen when pointing acc(2) to /sys/power/resume. At the point the where the write to this file happens the calling task has already exited and called exit_fs(). A lookup will thus trigger a NULL-deref when accessing current->fs. Reorganize the code so that the the final write happens from the workqueue but with the caller's credentials. This preserves the (strange) permission model and has almost no regression risk. This api should stop to exist though.

Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-21846, 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)