CVE-2025-40268
In the Linux kernel, the following vulnerability has been resolved: cifs: client: fix memory leak in smb3_fs_context_parse_param The user calls fsconfig twice, but when the program exits, free()…
Overview
CVE-2025-40268 is a known-severity vulnerability. It was published on December 6, 2025.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
cifs: client: fix memory leak in smb3_fs_context_parse_param
The user calls fsconfig twice, but when the program exits, free() only
frees ctx->source for the second fsconfig, not the first.
Regarding fc->source, there is no code in the fs context related to its
memory reclamation.
To fix this memory leak, release the source memory corresponding to ctx
or fc before each parsing.
syzbot reported:
BUG: memory leak
unreferenced object 0xffff888128afa360 (size 96):
backtrace (crc 79c9c7ba):
kstrdup+0x3c/0x80 mm/util.c:84
smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444
BUG: memory leak
unreferenced object 0xffff888112c7d900 (size 96):
backtrace (crc 79c9c7ba):
smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629
smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2025-40268?
CVE-2025-40268 is a known-severity vulnerability. It was published on December 6, 2025.
How severe is CVE-2025-40268?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2025-40268?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-40268?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-40268 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.