CVE-2025-21946: linux kernel Out-of-bounds Read — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds in parse_sec_desc() If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd struct size. If it is smaller, It could cause slab-out-of-bounds. And when validating sid, It need to check it included subauth array size.

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CVSS v3.1 Score

7.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.15 — 6.6.83
linux	linux_kernel	6.7 — 6.12.19
linux	linux_kernel	6.13 — 6.13.7
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/159d059cbcb0e6d0e7a7b34af3862ba09a6b22d1 https://git.kernel.org/stable/c/6a9831180d0b23b5c97e2bd841aefc8f82900172 https://git.kernel.org/stable/c/c1569dbbe2d43041be9f3fef7ca08bec3b66ad1b https://git.kernel.org/stable/c/d6e13e19063db24f94b690159d0633aaf72a0f03

Other References

https://git.kernel.org/stable/c/f4ee19528664777af8b842f8f001be98345aa973

Frequently Asked Questions

What is CVE-2025-21946? +

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bounds in parse_sec_desc() If osidoffset, gsidoffset and dacloffset could be greater than smb_ntsd struct size. If it is smaller, It could cause slab-out-of-bounds. And when validating sid, It need to check it included subauth array size. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2025-21946? +

CVE-2025-21946 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-21946? +

CVE-2025-21946 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21946? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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