CyberSecBulletin
CVE-2026-23447NVD status: Modified

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2026-23447 is a high-severity improper validation of array index 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 baf246d6680befde2086b1df9eb3aaba3fb6853f, 125f932a76a97904ef8a555f1dd53e5d0e288c54, af0d1613d6751489dbf9f69aac1123f0b1e566e5 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 baf246d6680befde2086b1df9eb3aaba3fb6853f or 125f932a76a97904ef8a555f1dd53e5d0e288c54 or af0d1613d6751489dbf9f69aac1123f0b1e566e5 or a5bd5a2710310c965ea4153cba4210988a3454e2, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.15 or 4.20 or 5.5 or 6.6.130, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, baf246d6680befde2086b1df9eb3aaba3fb6853f; 0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, 125f932a76a97904ef8a555f1dd53e5d0e288c54; 0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, af0d1613d6751489dbf9f69aac1123f0b1e566e5; 0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, a5bd5a2710310c965ea4153cba4210988a3454e2; 0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, de70da1fb1d152e981ecb3157f7ec2b633005c16; 0fa81b304a7973a499f844176ca031109487dd31 up to, but not including, 77914255155e68a20aa41175edeecf8121dac391; 8cf7db86a8984ffa3a3388a8df12bc0aa4c79bd7; 4ca8b8855264cf1439cdab3da7049bd1e3c2a9e6; and 5 more rangesbaf246d6680befde2086b1df9eb3aaba3fb6853f, 125f932a76a97904ef8a555f1dd53e5d0e288c54, af0d1613d6751489dbf9f69aac1123f0b1e566e5, a5bd5a2710310c965ea4153cba4210988a3454e2, de70da1fb1d152e981ecb3157f7ec2b633005c16, 77914255155e68a20aa41175edeecf8121dac391
LinuxLinux Kernel4.14.317 up to, but not including, 4.15; 4.19.285 up to, but not including, 4.20; 5.4.245 up to, but not including, 5.5; 5.7.1 up to, but not including, 6.6.130; 6.7 up to, but not including, 6.12.78; 6.13 up to, but not including, 6.18.20; 6.19 up to, but not including, 6.19.10; 5.7; and 1 more ranges4.15, 4.20, 5.5, 6.6.130, 6.12.78, 6.18.20

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 NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: net: usb: cdc_ncm: add ndpoffset to NDP32 nframes bounds check The same bounds-check bug fixed for NDP16 in the previous patch also exists in cdc_ncm_rx_verify_ndp32(). The DPE array size is validated against the total skb length without accounting for ndpoffset, allowing out-of-bounds reads when the NDP32 is placed near the end of the NTB. Add ndpoffset to the nframes bounds check and use struct_size_t() to express the NDP-plus-DPE-array size more clearly. Compile-tested only.

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

The underlying weakness: Improper Validation of Array Index

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How developers prevent this class of flaw

  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
  • Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.

More Improper Validation of Array Index vulnerabilities (CWE-129)

Timeline

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

References

Recent Improper Validation of Array Index vulnerabilities

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