CVE-2025-40291
In the Linux kernel, the following vulnerability has been resolved: io_uring: fix regbuf vector size truncation There is a report of io_estimate_bvec_size() truncating the calculated number of segments that leads to corruption issues. Check it doesn't overflow "int"s used later. Rough but simple, can be improved on top.
Affected versions
Linux kernel versions
6.15
and later are affected. Fixed in
6.17.8,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40291 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/146eb58629f45f8297e83d69e64d4eea4b28d972
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PatchKernel patch commithttps://git.kernel.org/stable/c/826ce37a842633efe1bb763e4b13045d74060d72
Frequently asked questions
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What is CVE-2025-40291?
CVE-2025-40291 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.15 onward and has been patched in 6.17.8 and 6.18. CVE-2025-40291 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-2025-40291?
Yes — CVE-2025-40291 has been patched. Fixed versions include 6.17.8 and 6.18. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40291 actively exploited?
No — CVE-2025-40291 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.