MEDIUM 6.7 Microsoft
CVE-2024-56738
GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
Microsoft Security Update 2026-Aug: GNU GRUB (aka GRUB2) through 2.12 does not use a constant-time algorithm for grub_crypto_memcmp and thus allows side-channel attacks.
Affected Products
- cbl2 grub2 2.06-14 on CBL Mariner 2.0
- azl3 grub2 2.06-24 on Azure Linux 3.0
- azl3 grub2 2.06-27 on Azure Linux 3.0
- cbl2 grub2 2.06-16
- cbl2 grub2 2.06-15 on CBL Mariner 2.0
- azl3 grub2 2.06-25 on Azure Linux 3.0
- cbl2 grub2 2.06-16 on CBL Mariner 2.0
- azl3 grub2 2.06-26 on Azure Linux 3.0
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-56738
- https://nvd.nist.gov/vuln/detail/CVE-2024-56738
This medium severity vulnerability with a CVSS score of 6.7 was published on 2026-08-06 via Microsoft. Affected: cbl2 grub2 2.06-14 on CBL Mariner 2.0, azl3 grub2 2.06-24 on Azure Linux 3.0, azl3 grub2 2.06-27 on Azure Linux 3.0 and 5 more.
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