CyberSecBulletin
CVE-2026-64598NVD status: Received

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-64598 is a high-severity integer overflow or wraparound vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions aa37f5fef78dd11cbf983269da2031e12625c56d, cad756733dc3985188983f3e2eb77e2927209099, a187883cc1dc784a4d32537f5d316f1b7b9ad76f 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 0.28% 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 aa37f5fef78dd11cbf983269da2031e12625c56d or cad756733dc3985188983f3e2eb77e2927209099 or a187883cc1dc784a4d32537f5d316f1b7b9ad76f or a1cc432cb0b0a1f74f98a0db3b94ca880c7947ac, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd08089f649a0cfb2099c8551ac47eef0cc23fdf2 up to, but not including, aa37f5fef78dd11cbf983269da2031e12625c56d; d08089f649a0cfb2099c8551ac47eef0cc23fdf2 up to, but not including, cad756733dc3985188983f3e2eb77e2927209099; d08089f649a0cfb2099c8551ac47eef0cc23fdf2 up to, but not including, a187883cc1dc784a4d32537f5d316f1b7b9ad76f; d08089f649a0cfb2099c8551ac47eef0cc23fdf2 up to, but not including, a1cc432cb0b0a1f74f98a0db3b94ca880c7947ac; d08089f649a0cfb2099c8551ac47eef0cc23fdf2 up to, but not including, 61f28012e5650c619223decdb7970e0d3162e949; 6.3aa37f5fef78dd11cbf983269da2031e12625c56d, cad756733dc3985188983f3e2eb77e2927209099, a187883cc1dc784a4d32537f5d316f1b7b9ad76f, a1cc432cb0b0a1f74f98a0db3b94ca880c7947ac, 61f28012e5650c619223decdb7970e0d3162e949

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: smb/client: Fix error code in smb2_aead_req_alloc() The "*num_sgs" variable is a u32 so "ERR_PTR(*num_sgs)" doesn't work. We would have to do something similar to the previous line where it's cast to int and then long. However, it's simpler to store the return in an int ret variable. This bug would eventually result in a crash when dereference the invalid error pointer.

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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