CVE-2025-40279
In the Linux kernel, the following vulnerability has been resolved: net: sched: act_connmark: initialize struct tc_ife to fix kernel leak In tcf_connmark_dump(), the variable 'opt' was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace. Initialize the structure with memset before assigning its fields to ensure all members and padding are cleared prior to beign copied.
Affected versions
Linux kernel versions
4.0
and later are affected. Fixed in
5.15.197,
6.1.159,
6.6.117,
6.12.59,
6.17.9,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40279 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/218b67c8c8246d47a2a7910eae80abe4861fe2b7
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PatchKernel patch commithttps://git.kernel.org/stable/c/25837889ec062f2b7618142cd80253dff3da5343
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PatchKernel patch commithttps://git.kernel.org/stable/c/31e4aa93e2e5b5647fc235b0f6ee329646878f9e
Frequently asked questions
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What is CVE-2025-40279?
CVE-2025-40279 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.0 onward and has been patched in 5.15.197, 6.1.159, 6.6.117 and others. CVE-2025-40279 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2025-40279?
Yes — CVE-2025-40279 has been patched. Fixed versions include 5.15.197, 6.1.159, 6.6.117 and others. If you are running Linux kernel 4.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40279 actively exploited?
No — CVE-2025-40279 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.