CVE-2025-21763
HighIn the Linux kernel, the following vulnerability has been resolved: neighbour: use RCU protection in __neigh_notify() __neigh_notify() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2025-21763 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.25
and later are affected. Fixed in
5.4.291,
5.10.235,
5.15.179,
6.1.129,
6.6.79,
6.12.16,
6.13.4,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21763 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/1cbb2aa90cd3fba15ad7efb5cdda28f3d1082379
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PatchKernel patch commithttps://git.kernel.org/stable/c/40d8f2f2a373b6c294ffac394d2bb814b572ead1
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PatchKernel patch commithttps://git.kernel.org/stable/c/559307d25235e24b5424778c7332451b6c741159
Frequently asked questions
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What is CVE-2025-21763?
CVE-2025-21763 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 2.6.25 onward and has been patched in 5.4.291, 5.10.235, 5.15.179 and others. CVE-2025-21763 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-2025-21763?
CVE-2025-21763 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2025-21763?
Yes — CVE-2025-21763 has been patched. Fixed versions include 5.4.291, 5.10.235, 5.15.179 and others. If you are running Linux kernel 2.6.25 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21763 actively exploited?
No — CVE-2025-21763 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 Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →