CyberSecBulletin
CVE-2026-43059NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-43059 is a high-severity use after free 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 3d6de8467236cd763ddc7d06127689bdfbfbd8ff, 695b45b2262fcb5e71bed1175aad59c72f92aa78, b5c5e96f3b0a5003c3ff98ebb33e59afec51dd77 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 3d6de8467236cd763ddc7d06127689bdfbfbd8ff or 695b45b2262fcb5e71bed1175aad59c72f92aa78 or b5c5e96f3b0a5003c3ff98ebb33e59afec51dd77 or 02023ff760cc104a5d86a82ef5b8dd89098ad78d, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.7 or 6.12.78 or 6.17 or 6.18.20, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0b60eb04b8524e1b4b3f07fea0d16fda9a677d9a up to, but not including, 3d6de8467236cd763ddc7d06127689bdfbfbd8ff; d71b98f253b079cbadc83266383f26fe7e9e103b up to, but not including, 695b45b2262fcb5e71bed1175aad59c72f92aa78; 302a1f674c00dd5581ab8e493ef44767c5101aab up to, but not including, b5c5e96f3b0a5003c3ff98ebb33e59afec51dd77; 302a1f674c00dd5581ab8e493ef44767c5101aab up to, but not including, 02023ff760cc104a5d86a82ef5b8dd89098ad78d; 302a1f674c00dd5581ab8e493ef44767c5101aab up to, but not including, 17f89341cb4281d1da0e2fb0de5406ab7c4e25ef; 87a1f16f07c6c43771754075e08f45b41d237421; 6.6.140 up to, but not including, 6.6.160; 6.12.59 up to, but not including, 6.12.78; and 2 more ranges3d6de8467236cd763ddc7d06127689bdfbfbd8ff, 695b45b2262fcb5e71bed1175aad59c72f92aa78, b5c5e96f3b0a5003c3ff98ebb33e59afec51dd77, 02023ff760cc104a5d86a82ef5b8dd89098ad78d, 17f89341cb4281d1da0e2fb0de5406ab7c4e25ef, 6.6.160
LinuxLinux Kernel6.6.140 up to, but not including, 6.7; 6.12.59 up to, but not including, 6.12.78; 6.16.10 up to, but not including, 6.17; 6.17.1 up to, but not including, 6.18.20; 6.19 up to, but not including, 6.19.10; 6.17; 7.06.7, 6.12.78, 6.17, 6.18.20, 6.19.10

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: Bluetooth: MGMT: Fix list corruption and UAF in command complete handlers Commit 302a1f674c00 ("Bluetooth: MGMT: Fix possible UAFs") introduced mgmt_pending_valid(), which not only validates the pending command but also unlinks it from the pending list if it is valid. This change in semantics requires updates to several completion handlers to avoid list corruption and memory safety issues. This patch addresses two left-over issues from the aforementioned rework: 1. In mgmt_add_adv_patterns_monitor_complete(), mgmt_pending_remove() is replaced with mgmt_pending_free() in the success path. Since mgmt_pending_valid() already unlinks the command at the beginning of the function, calling mgmt_pending_remove() leads to a double list_del() and subsequent list corruption/kernel panic. 2. In set_mesh_complete(), the use of mgmt_pending_foreach() in the error path is removed. Since the current command is already unlinked by mgmt_pending_valid(), this foreach loop would incorrectly target other pending mesh commands, potentially freeing them while they are still being processed concurrently (leading to UAFs). The redundant mgmt_cmd_status() is also simplified to use cmd->opcode directly.

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. 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 Use After Free vulnerabilities

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