CVE-2025-21669
MediumIn the Linux kernel, the following vulnerability has been resolved: vsock/virtio: discard packets if the transport changes If the socket has been de-assigned or assigned to another transport, we must discard any packets received because they are not expected and would cause issues when we access vsk->transport. A possible scenario is described by Hyunwoo Kim in the attached link, where after a first connect() interrupted by a signal, and a second connect() failed, we can find `vsk->transport` at NULL, leading to a NULL pointer dereference.
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-476CVE-2025-21669 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.5
and later are affected. Fixed in
5.10.234,
5.15.177,
6.1.127,
6.6.74,
6.12.11,
6.13
and their respective stable series.
References
The following references provide additional information about CVE-2025-21669 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/18a7fc371d1dbf8deff16c2dd9292bcc73f43040
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PatchKernel patch commithttps://git.kernel.org/stable/c/2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1
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PatchKernel patch commithttps://git.kernel.org/stable/c/6486915fa661584d70e8e7e4068c6c075c67dd6d
Frequently asked questions
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What is CVE-2025-21669?
CVE-2025-21669 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.5 onward and has been patched in 5.10.234, 5.15.177, 6.1.127 and others. CVE-2025-21669 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-2025-21669?
CVE-2025-21669 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-2025-21669?
Yes — CVE-2025-21669 has been patched. Fixed versions include 5.10.234, 5.15.177, 6.1.127 and others. If you are running Linux kernel 5.5 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21669 actively exploited?
No — CVE-2025-21669 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 NULL Pointer Dereference (CWE-476)?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →