CyberSecBulletin
CVE-2026-64273NVD status: Analyzed

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2026-64273 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 b1b79e89bc33e4c682d3df7ae2aadc62b5a0c310, d10b0507fa0f5b46764b178e3271f9012f2df677, 6c0f2901c9d325d4a0574c4237fd507810d225ff 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 0.17% 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 b1b79e89bc33e4c682d3df7ae2aadc62b5a0c310 or d10b0507fa0f5b46764b178e3271f9012f2df677 or 6c0f2901c9d325d4a0574c4237fd507810d225ff or c21295616a8a52b9a5f18cd4ca8c73030eda3d4f, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.261 or 5.15.212 or 6.1.178 or 6.6.145, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, b1b79e89bc33e4c682d3df7ae2aadc62b5a0c310; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, d10b0507fa0f5b46764b178e3271f9012f2df677; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 6c0f2901c9d325d4a0574c4237fd507810d225ff; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, c21295616a8a52b9a5f18cd4ca8c73030eda3d4f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, e5fa31f0550b55d80045669ae9080dd5b88abffa; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 70019779325f2bb5f5a4098e91e79c655f50fcef; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, a40250f97c312e000e3616c9074022311a0efbc3; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 0e9943d2e4c63496b6ca84bc66fd3c71d40558e2; and 1 more rangesb1b79e89bc33e4c682d3df7ae2aadc62b5a0c310, d10b0507fa0f5b46764b178e3271f9012f2df677, 6c0f2901c9d325d4a0574c4237fd507810d225ff, c21295616a8a52b9a5f18cd4ca8c73030eda3d4f, e5fa31f0550b55d80045669ae9080dd5b88abffa, 70019779325f2bb5f5a4098e91e79c655f50fcef
LinuxLinux Kernel2.6.12.1 up to, but not including, 5.10.261; 5.11 up to, but not including, 5.15.212; 5.16 up to, but not including, 6.1.178; 6.2 up to, but not including, 6.6.145; 6.7 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; 2.6.125.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39

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: Input: iforce - bound the device-reported force-feedback effect index iforce_process_packet() handles a status report (packet id 0x02) by taking a force-feedback effect index straight from the device wire and using it to address the per-effect state array: i = data[1] & 0x7f; if (data[1] & 0x80) { if (!test_and_set_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) ... } else if (test_and_clear_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) { ... } The index is masked only with 0x7f, so it ranges 0..127, but core_effects[] holds only IFORCE_EFFECTS_MAX (32) entries. For an index of 32..127 the test_and_set_bit()/test_and_clear_bit() is an out-of-bounds single-bit read-modify-write past the array. core_effects[] is the second-to-last member of struct iforce, so the write lands in the trailing members and beyond the embedding kzalloc()'d iforce_serio / iforce_usb object. data[1] is unvalidated device payload on both transports (the USB interrupt endpoint and serio), and the status path is not gated on force feedback being present, so a malicious or counterfeit device can set or clear a bit at an attacker-chosen offset past the object. Reject an out-of-range index instead of indexing with it. Bound against the array dimension IFORCE_EFFECTS_MAX rather than dev->ff->max_effects so the check guarantees memory safety regardless of how many effects the device registered. A legitimate "effect started/stopped" status always carries an index below IFORCE_EFFECTS_MAX, so well-formed devices are unaffected; the neighbouring mark_core_as_ready() loop is already bounded and is left untouched.

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. Record last changed materially (score, affected products, status or references).

References

Recent Improper Validation of Array Index vulnerabilities

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