#VU106656 Out-of-bounds read in Linux kernel - CVE-2025-21946


| Updated: 2025-05-11

Vulnerability identifier: #VU106656

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-21946

CWE-ID: CWE-125

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to an out-of-bounds read error within the parse_sid() and parse_sec_desc() functions in fs/smb/server/smbacl.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 6.6, 6.6 rc1, 6.6 rc2, 6.6 rc3, 6.6 rc4, 6.6 rc5, 6.6 rc6, 6.6.1, 6.6.2, 6.6.3, 6.6.4, 6.6.5, 6.6.6, 6.6.7, 6.6.8, 6.6.9, 6.6.10, 6.6.11, 6.6.12, 6.6.13, 6.6.14, 6.6.15, 6.6.16, 6.6.17, 6.6.18, 6.6.19, 6.6.20, 6.6.21, 6.6.22, 6.6.23, 6.6.24, 6.6.25, 6.6.26, 6.6.27, 6.6.28, 6.6.29, 6.6.30, 6.6.31, 6.6.32, 6.6.33, 6.6.34, 6.6.35, 6.6.36, 6.6.37, 6.6.38, 6.6.39, 6.6.40, 6.6.41, 6.6.42, 6.6.43, 6.6.44, 6.6.45, 6.6.46, 6.6.47, 6.6.48, 6.6.49, 6.6.50, 6.6.51, 6.6.52, 6.6.53, 6.6.54, 6.6.55, 6.6.56, 6.6.57, 6.6.58, 6.6.59, 6.6.60, 6.6.61, 6.6.62, 6.6.63, 6.6.64, 6.6.65, 6.6.66, 6.6.67, 6.6.68, 6.6.69, 6.6.70, 6.6.71, 6.6.72, 6.6.73, 6.6.74, 6.6.75, 6.6.76, 6.6.77, 6.6.78, 6.6.79, 6.6.80, 6.6.81, 6.6.82, 6.12, 6.12.1, 6.12.2, 6.12.3, 6.12.4, 6.12.5, 6.12.6, 6.12.7, 6.12.8, 6.12.9, 6.12.10, 6.12.11, 6.12.12, 6.12.13, 6.12.14, 6.12.15, 6.12.16, 6.12.17, 6.12.18, 6.13, 6.13.1, 6.13.2, 6.13.3, 6.13.4, 6.13.5, 6.13.6


External links
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
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.19
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.7
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.14
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.83


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.


Latest bulletins with this vulnerability