CVE-2025-21978
MediumIn the Linux kernel, the following vulnerability has been resolved: drm/hyperv: Fix address space leak when Hyper-V DRM device is removed When a Hyper-V DRM device is probed, the driver allocates MMIO space for the vram, and maps it cacheable. If the device removed, or in the error path for device probing, the MMIO space is released but no unmap is done. Consequently the kernel address space for the mapping is leaked. Fix this by adding iounmap() calls in the device removal path, and in the error path during device probing.
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-401CVE-2025-21978 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
6.0
and later are affected. Fixed in
6.1.132,
6.6.84,
6.12.20,
6.13.8,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21978 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/158242b56bf465a73e1edeac0fe828a8acad4499
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PatchKernel patch commithttps://git.kernel.org/stable/c/24f1bbfb2be77dad82489c1468bbb14312aab129
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PatchKernel patch commithttps://git.kernel.org/stable/c/ad27b4a51495490b815580d9b935e8eee14d1a9c
Frequently asked questions
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What is CVE-2025-21978?
CVE-2025-21978 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 6.0 onward and has been patched in 6.1.132, 6.6.84, 6.12.20 and others. CVE-2025-21978 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-2025-21978?
CVE-2025-21978 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-2025-21978?
Yes — CVE-2025-21978 has been patched. Fixed versions include 6.1.132, 6.6.84, 6.12.20 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21978 actively exploited?
No — CVE-2025-21978 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 Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →