CyberSecBulletin
CVE-2026-63881NVD status: Analyzed

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-63881 is a high-severity integer overflow or wraparound vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 4e5f808b454167cc58d7084a407a554d8ddc694d, de70a80992396ee306ee3a2810ad28aa1608ba9b, 5cf4a41aa0d74e4c83f82d2ce233b5189ed4b43c as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 4e5f808b454167cc58d7084a407a554d8ddc694d or de70a80992396ee306ee3a2810ad28aa1608ba9b or 5cf4a41aa0d74e4c83f82d2ce233b5189ed4b43c or 4f9eeedc3d3151f8a226fd676c314a813edda5a1, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.143 or 6.12.93 or 6.18.35 or 7.0.12, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa70a93fa568b4f05aba548dadb673703eccf5480 up to, but not including, 4e5f808b454167cc58d7084a407a554d8ddc694d; a70a93fa568b4f05aba548dadb673703eccf5480 up to, but not including, de70a80992396ee306ee3a2810ad28aa1608ba9b; a70a93fa568b4f05aba548dadb673703eccf5480 up to, but not including, 5cf4a41aa0d74e4c83f82d2ce233b5189ed4b43c; a70a93fa568b4f05aba548dadb673703eccf5480 up to, but not including, 4f9eeedc3d3151f8a226fd676c314a813edda5a1; a70a93fa568b4f05aba548dadb673703eccf5480 up to, but not including, 93f5534b35a05ef8a0109c1eefa800062fee810a; 6.54e5f808b454167cc58d7084a407a554d8ddc694d, de70a80992396ee306ee3a2810ad28aa1608ba9b, 5cf4a41aa0d74e4c83f82d2ce233b5189ed4b43c, 4f9eeedc3d3151f8a226fd676c314a813edda5a1, 93f5534b35a05ef8a0109c1eefa800062fee810a
LinuxLinux Kernel6.5 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.16.6.143, 6.12.93, 6.18.35, 7.0.12

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix a vulnerability of integer overflow in kfd debugger get_queue_ids() computes array_size = num_queues * sizeof(uint32_t), which could overflow on 32-bit size_t build. using array_size() instead, it saturates to SIZE_MAX on overflow. (cherry picked from commit 2d57a0475f085c08b49312dfd8edcb461845f285)

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Integer Overflow or Wraparound vulnerabilities

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