CVE-2026-31716
HighIn the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate rec->used in journal-replay file record check check_file_record() validates rec->total against the record size but never validates rec->used. The do_action() journal-replay handlers read rec->used from disk and use it to compute memmove lengths: DeleteAttribute: memmove(attr, ..., used - asize - roff) CreateAttribute: memmove(..., attr, used - roff) change_attr_size: memmove(..., used - PtrOffset(rec, next)) When rec->used is smaller than the offset of a validated attribute, or larger than the record size, these subtractions can underflow allowing us to copy huge amounts of memory in to a 4kb buffer, generally considered a bad idea overall. This requires a corrupted filesystem, which isn't a threat model the kernel really needs to worry about, but checking for such an obvious out-of-bounds value is good to keep things robust, especially on journal replay Fix this up by bounding rec->used correctly. This is much like commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") which checked different values in this same switch statement.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness type
CWE-787CVE-2026-31716 is a Out-of-bounds Write vulnerability
What is Out-of-bounds Write?
The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.15
and later are affected. Fixed in
5.15.209,
6.1.175,
6.6.136,
6.12.84,
6.18.25,
7.0.2,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-31716 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/0112e6279420d4005b3d57af36fb45c01b8d0116
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PatchKernel patch commithttps://git.kernel.org/stable/c/0ca0485e4b2e837ebb6cbd4f2451aba665a03e4b
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PatchKernel patch commithttps://git.kernel.org/stable/c/1393a467a9607e62123806de7d4c3a3e54e396a9
Frequently asked questions
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What is CVE-2026-31716?
CVE-2026-31716 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 5.15 onward and has been patched in 5.15.209, 6.1.175, 6.6.136 and others. CVE-2026-31716 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-2026-31716?
CVE-2026-31716 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:N/UI:R/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2026-31716?
Yes — CVE-2026-31716 has been patched. Fixed versions include 5.15.209, 6.1.175, 6.6.136 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-31716 actively exploited?
No — CVE-2026-31716 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 Out-of-bounds Write (CWE-787)?
The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →