What is CVE-2025-40268?

CVE-2025-40268 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 5.11 onward and patched in 6.6.117, 6.12.59, 6.17.9 and others. CVE-2025-40268 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-40268?

CVE-2025-40268 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2025-40268?

Yes, CVE-2025-40268 has been patched. Fixed versions include 6.6.117, 6.12.59, 6.17.9 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-40268 actively exploited?

CVE-2025-40268 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

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() 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

Package Linux Kernel

Published 2025-12-06

Last modified 2026-04-15

Patch available

Yes

Affected versions

Linux kernel versions 5.11 and later are affected. Fixed in 6.6.117, 6.12.59, 6.17.9, 6.18 and their respective stable series.

Affected from

≥ 5.11

Fixed in

✓ 6.6.117 6.6.x ✓ 6.12.59 6.12.x ✓ 6.17.9 6.17.x ✓ 6.18

References

The following references provide additional information about CVE-2025-40268 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/4515743cc7a42e1d67468402a6420c195532a6fa
Patch
Kernel patch commit
https://git.kernel.org/stable/c/48c17341577e25a22feb13d694374b61d974edbc
Patch
Kernel patch commit
https://git.kernel.org/stable/c/868fc62811d3fabcf5685e14f36377a855d5412d
Patch

4 patch commits total View all on NVD

Frequently asked questions

What is CVE-2025-40268?

CVE-2025-40268 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.11 onward and has been patched in 6.6.117, 6.12.59, 6.17.9 and others. CVE-2025-40268 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2025-40268?

Yes — CVE-2025-40268 has been patched. Fixed versions include 6.6.117, 6.12.59, 6.17.9 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-40268 actively exploited?

No — CVE-2025-40268 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.