CVE-2026-31400
MediumIn the Linux kernel, the following vulnerability has been resolved: sunrpc: fix cache_request leak in cache_release When a reader's file descriptor is closed while in the middle of reading a cache_request (rp->offset != 0), cache_release() decrements the request's readers count but never checks whether it should free the request. In cache_read(), when readers drops to 0 and CACHE_PENDING is clear, the cache_request is removed from the queue and freed along with its buffer and cache_head reference. cache_release() lacks this cleanup. The only other path that frees requests with readers == 0 is cache_dequeue(), but it runs only when CACHE_PENDING transitions from set to clear. If that transition already happened while readers was still non-zero, cache_dequeue() will have skipped the request, and no subsequent call will clean it up. Add the same cleanup logic from cache_read() to cache_release(): after decrementing readers, check if it reached 0 with CACHE_PENDING clear, and if so, dequeue and free the cache_request.
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-2026-31400 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
2.6.12
and later are affected. Fixed in
5.10.253,
5.15.203,
6.1.167,
6.6.130,
6.12.78,
6.18.20,
6.19.10,
7.0
and their respective stable series.
References
The following references provide additional information about CVE-2026-31400 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/17ad31b3a43b72aec3a3d83605891e1397d0d065
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PatchKernel patch commithttps://git.kernel.org/stable/c/1dfedb293943e491379c9302b428e6f920a73d12
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PatchKernel patch commithttps://git.kernel.org/stable/c/301670dcd098c1fe5c2fe90fb3c7a8f4814d2351
Frequently asked questions
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What is CVE-2026-31400?
CVE-2026-31400 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 2.6.12 onward and has been patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2026-31400 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-2026-31400?
CVE-2026-31400 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-2026-31400?
Yes — CVE-2026-31400 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31400 actively exploited?
No — CVE-2026-31400 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 →