CyberSecBulletin
CVE-2026-43250NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-43250 is a high-severity out-of-bounds write 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 1497998749600411d75e60a44f7e572b2348bd9a, aad97c92119cb85db105ddda4a44c86cc0748e8c, 1b72b834511d17f4d069d512f78671f3f210a2f1 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 0.16% 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 1497998749600411d75e60a44f7e572b2348bd9a or aad97c92119cb85db105ddda4a44c86cc0748e8c or 1b72b834511d17f4d069d512f78671f3f210a2f1 or f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12.75 or 6.18.16 or 6.19.6, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxaa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, 1497998749600411d75e60a44f7e572b2348bd9a; aa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, aad97c92119cb85db105ddda4a44c86cc0748e8c; aa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, 1b72b834511d17f4d069d512f78671f3f210a2f1; aa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec; aa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, e74c436f8568af1c60942469d0a2300b3ada3857; aa69a8093ff985873cb44fe1157bd6db29a20fe4 up to, but not including, cea2a1257a3b5ea3e769a445b34af13e6aa5a123; 2.6.291497998749600411d75e60a44f7e572b2348bd9a, aad97c92119cb85db105ddda4a44c86cc0748e8c, 1b72b834511d17f4d069d512f78671f3f210a2f1, f4fbf2d4750d12ac8525d2efac1016fa0d84d4ec, e74c436f8568af1c60942469d0a2300b3ada3857, cea2a1257a3b5ea3e769a445b34af13e6aa5a123
LinuxLinux Kernel2.6.29 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.16; 6.19 up to, but not including, 6.19.66.12.75, 6.18.16, 6.19.6

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: usb: chipidea: udc: fix DMA and SG cleanup in _ep_nuke() The ChipIdea UDC driver can encounter "not page aligned sg buffer" errors when a USB device is reconnected after being disconnected during an active transfer. This occurs because _ep_nuke() returns requests to the gadget layer without properly unmapping DMA buffers or cleaning up scatter-gather bounce buffers. Root cause: When a disconnect happens during a multi-segment DMA transfer, the request's num_mapped_sgs field and sgt.sgl pointer remain set with stale values. The request is returned to the gadget driver with status -ESHUTDOWN but still has active DMA state. If the gadget driver reuses this request on reconnect without reinitializing it, the stale DMA state causes _hardware_enqueue() to skip DMA mapping (seeing non-zero num_mapped_sgs) and attempt to use freed/invalid DMA addresses, leading to alignment errors and potential memory corruption. The normal completion path via _hardware_dequeue() properly calls usb_gadget_unmap_request_by_dev() and sglist_do_debounce() before returning the request. The _ep_nuke() path must do the same cleanup to ensure requests are returned in a clean, reusable state. Fix: Add DMA unmapping and bounce buffer cleanup to _ep_nuke() to mirror the cleanup sequence in _hardware_dequeue(): - Call usb_gadget_unmap_request_by_dev() if num_mapped_sgs is set - Call sglist_do_debounce() with copy=false if bounce buffer exists This ensures that when requests are returned due to endpoint shutdown, they don't retain stale DMA mappings. The 'false' parameter to sglist_do_debounce() prevents copying data back (appropriate for shutdown path where transfer was aborted).

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

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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