CVE-2025-21853MediumMicrosoft 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-2025-21853

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-2025-21853. This page also shows what EchelonGraph holds for CVE-2025-21853, 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 products4

  • 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 5.15.182.1-1 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 Update5.15.182.1-1
—Security Update—

🧭 EchelonGraph on CVE-2025-21853

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: bpf: avoid holding freeze_mutex during mmap operation We use map->freeze_mutex to prevent races between map_freeze() and memory mapping BPF map contents with writable permissions. The way we naively do this means we'll hold freeze_mutex for entire duration of all the mm and VMA manipulations, which is completely unnecessary. This can potentially also lead to deadlocks, as reported by syzbot in [0]. So, instead, hold freeze_mutex only during writeability checks, bump (proactively) "write active" count for the map, unlock the mutex and proceed with mmap logic. And only if something went wrong during mmap logic, then undo that "write active" counter increment. [0] https://lore.kernel.org/bpf/[email protected]/

Published by kernel.org, the CVE Numbering Authority that assigned CVE-2025-21853, 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)