CVE-2025-21736
MediumIn the Linux kernel, the following vulnerability has been resolved: nilfs2: fix possible int overflows in nilfs_fiemap() Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result by being prepared to go through potentially maxblocks == INT_MAX blocks, the value in n may experience an overflow caused by left shift of blkbits. While it is extremely unlikely to occur, play it safe and cast right hand expression to wider type to mitigate the issue. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-190CVE-2025-21736 is a Integer Overflow vulnerability
What is Integer Overflow?
The product performs a calculation that can produce an integer overflow, leading to unexpected values. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.38
and later are affected. Fixed in
5.4.291,
5.10.235,
5.15.179,
6.1.129,
6.6.78,
6.12.14,
6.13.3,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21736 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/250423300b4b0335918be187ef3cade248c06e6a
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PatchKernel patch commithttps://git.kernel.org/stable/c/58b1c6881081f5ddfb9a14dc241a74732c0f855c
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PatchKernel patch commithttps://git.kernel.org/stable/c/6438ef381c183444f7f9d1de18f22661cba1e946
Frequently asked questions
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What is CVE-2025-21736?
CVE-2025-21736 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Integer Overflow flaw (CWE-190) . It affects Linux kernel versions from 2.6.38 onward and has been patched in 5.4.291, 5.10.235, 5.15.179 and others. CVE-2025-21736 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-21736?
CVE-2025-21736 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-21736?
Yes — CVE-2025-21736 has been patched. Fixed versions include 5.4.291, 5.10.235, 5.15.179 and others. If you are running Linux kernel 2.6.38 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21736 actively exploited?
No — CVE-2025-21736 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Integer Overflow (CWE-190)?
The product performs a calculation that can produce an integer overflow, leading to unexpected values. View CWE-190 on MITRE CWE →