CyberSecBulletin
CVE-2026-23281NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-23281 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 b15e0fa7adb4de3a03aee9e6fc4d83e5cf0a65e4, 09f3c30ab3b1371eaf9676a1b8add57bca763083, 3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc 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 0.14% 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 b15e0fa7adb4de3a03aee9e6fc4d83e5cf0a65e4 or 09f3c30ab3b1371eaf9676a1b8add57bca763083 or 3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc or 3c5c818c78b03a1725f3dcd566865c77b48dd3a6, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.167 or 6.6.130, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, b15e0fa7adb4de3a03aee9e6fc4d83e5cf0a65e4; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, 09f3c30ab3b1371eaf9676a1b8add57bca763083; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, 3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, 3c5c818c78b03a1725f3dcd566865c77b48dd3a6; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, d0155fe68f31b339961cf2d4f92937d57e9384e6; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, ed7d30f90b77f73a47498686ede83f622b7e4f0d; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, a9f55b14486426d907459bced5825a25063bd922; 954ee164f4f4598afc172c0ec3865d0352e55a0b up to, but not including, 03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0; and 1 more rangesb15e0fa7adb4de3a03aee9e6fc4d83e5cf0a65e4, 09f3c30ab3b1371eaf9676a1b8add57bca763083, 3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc, 3c5c818c78b03a1725f3dcd566865c77b48dd3a6, d0155fe68f31b339961cf2d4f92937d57e9384e6, ed7d30f90b77f73a47498686ede83f622b7e4f0d
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel2.6.24 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.167; 6.2 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, 6.18.17; 6.19 up to, but not including, 6.19.7; 7.05.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.17

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: wifi: libertas: fix use-after-free in lbs_free_adapter() The lbs_free_adapter() function uses timer_delete() (non-synchronous) for both command_timer and tx_lockup_timer before the structure is freed. This is incorrect because timer_delete() does not wait for any running timer callback to complete. If a timer callback is executing when lbs_free_adapter() is called, the callback will access freed memory since lbs_cfg_free() frees the containing structure immediately after lbs_free_adapter() returns. Both timer callbacks (lbs_cmd_timeout_handler and lbs_tx_lockup_handler) access priv->driver_lock, priv->cur_cmd, priv->dev, and other fields, which would all be use-after-free violations. Use timer_delete_sync() instead to ensure any running timer callback has completed before returning. This bug was introduced in commit 8f641d93c38a ("libertas: detect TX lockups and reset hardware") where del_timer() was used instead of del_timer_sync() in the cleanup path. The command_timer has had the same issue since the driver was first written.

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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