MEDIUM 5.5 Microsoft

CVE-2025-21673

smb: client: fix double free of TCP_Server_Info::hostname

Microsoft Security Update 2026-Aug: smb: client: fix double free of TCP_Server_Info::hostname

Affected Products

azl3 kernel 6.6.64.2-9 on Azure Linux 3.0
cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0
cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0
cbl2 kernel 5.15.202.1-1
azl3 kernel 6.6.76.1-1 on Azure Linux 3.0
cbl2 kernel 5.15.200.1-1 on CBL Mariner 2.0

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21673
https://nvd.nist.gov/vuln/detail/CVE-2025-21673

Published: 2026-08-06 · Source: Microsoft · Feed updated: 2026-08-10

This medium severity vulnerability with a CVSS score of 5.5 was published on 2026-08-06 via Microsoft. Affected: azl3 kernel 6.6.64.2-9 on Azure Linux 3.0, cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0, cbl2 kernel 5.15.202.1-1 on CBL Mariner 2.0 and 3 more.

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