CyberSecBulletin
CVE-2026-64354NVD status: Modified

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-64354 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 c5ff816d5f13900c3f1f3298cfcc61339e056e56, cd407de2ef5dc70f1970b343ffaa16186340fdfd, ff77d013b737c0f77d925e2f2c59f0cf3d76bd35 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 0.13% 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 c5ff816d5f13900c3f1f3298cfcc61339e056e56 or cd407de2ef5dc70f1970b343ffaa16186340fdfd or ff77d013b737c0f77d925e2f2c59f0cf3d76bd35 or b9452b594fd3aecbfd4aa0a6a1f741330a37dab7, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12 or 6.12.96 or 6.18.39 or 7.1.4, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux797d73ee232dd1833dec4824bc53a22032e97c1c up to, but not including, c5ff816d5f13900c3f1f3298cfcc61339e056e56; 797d73ee232dd1833dec4824bc53a22032e97c1c up to, but not including, cd407de2ef5dc70f1970b343ffaa16186340fdfd; 797d73ee232dd1833dec4824bc53a22032e97c1c up to, but not including, ff77d013b737c0f77d925e2f2c59f0cf3d76bd35; 797d73ee232dd1833dec4824bc53a22032e97c1c up to, but not including, b9452b594fd3aecbfd4aa0a6a1f741330a37dab7; 6f957d972feee9b385ea3ae6530310a84e55ba71; 6.11.6 up to, but not including, 6.12; 6.12c5ff816d5f13900c3f1f3298cfcc61339e056e56, cd407de2ef5dc70f1970b343ffaa16186340fdfd, ff77d013b737c0f77d925e2f2c59f0cf3d76bd35, b9452b594fd3aecbfd4aa0a6a1f741330a37dab7, 6.12
LinuxLinux Kernel6.11.6 up to, but not including, 6.12; 6.12.1 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4; 6.126.12, 6.12.96, 6.18.39, 7.1.4

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: bpf: Validate BTF repeated field counts before expansion btf_parse_struct_metas() walks user-supplied BTF during BPF_BTF_LOAD, and btf_repeat_fields() expands repeatable fields from array elements into the fixed BTF_FIELDS_MAX scratch array used by btf_parse_fields(). The remaining-capacity check performs the expanded field count calculation in u32. A malformed BTF can wrap that calculation, causing the check to pass even when the expanded field count exceeds the scratch array capacity. The following memcpy() can then write past the end of the array. Use checked addition and multiplication before copying repeated fields and reject impossible counts.

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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