CyberSecBulletin
CVE-2026-43497NVD status: Analyzed

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-43497 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists versions 60f711cfd580f86fea8284146ac133804e728f9a, 5931f5651ee32bd41b3323256b31fcc8e71336ed, e3d9865dacd7435b8465848428210d0f0c673311 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 0.11% 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 60f711cfd580f86fea8284146ac133804e728f9a or 5931f5651ee32bd41b3323256b31fcc8e71336ed or e3d9865dacd7435b8465848428210d0f0c673311 or 4f312c30f0368e8d2a76aa650dff73f23490b5e7, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.140, whichever matches your release line, or a later version.
  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
LinuxLinux7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, 60f711cfd580f86fea8284146ac133804e728f9a; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, 5931f5651ee32bd41b3323256b31fcc8e71336ed; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, e3d9865dacd7435b8465848428210d0f0c673311; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, 4f312c30f0368e8d2a76aa650dff73f23490b5e7; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, 18dd358de72d57993422cbb5dfb29ccd74efe192; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, da9b065cedfd3b574f229d5be594e6aa47a27ae6; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, a2c53a3822ee26e8d758071815b9ed3bf6669fc1; 7433914efd584b22bb49d3e1eee001f5d0525ecd up to, but not including, 8de779dc40d35d39fa07387b6f921eb11df0f511; and 1 more ranges60f711cfd580f86fea8284146ac133804e728f9a, 5931f5651ee32bd41b3323256b31fcc8e71336ed, e3d9865dacd7435b8465848428210d0f0c673311, 4f312c30f0368e8d2a76aa650dff73f23490b5e7, 18dd358de72d57993422cbb5dfb29ccd74efe192, da9b065cedfd3b574f229d5be594e6aa47a27ae6
LinuxLinux Kernel4.19 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.7; 7.15.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30

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
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:L/AC:L/PR:L/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: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation.

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

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

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

References

Recent Use After Free vulnerabilities

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