CVE-2026-31716

High

In 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.

Package Linux Kernel
Published 2026-05-01
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness type

CWE-787

CVE-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.

Affected from
≥ 5.15
Fixed in
✓ 5.15.209 5.15.x ✓ 6.1.175 6.1.x ✓ 6.6.136 6.6.x ✓ 6.12.84 6.12.x ✓ 6.18.25 6.18.x ✓ 7.0.2 7.0.x ✓ 7.1-rc1

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.

Frequently asked questions

  • 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.

  • 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.

  • 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.

  • 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 →