CyberSecBulletin
CVE-2026-64329NVD status: Analyzed

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-64329 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 f1adeb1ff8bef1467d6961059810795d02bbad5d, 99381e762273a2410a3f0216000be32b013c0ea9, 1a160076d3d0dcd4a98a4599ad96eec0790b099b 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 0.13% 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 f1adeb1ff8bef1467d6961059810795d02bbad5d or 99381e762273a2410a3f0216000be32b013c0ea9 or 1a160076d3d0dcd4a98a4599ad96eec0790b099b or c32df11147822d22facee8fa30c2e8971d12f426, 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
LinuxLinuxe32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, f1adeb1ff8bef1467d6961059810795d02bbad5d; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, 99381e762273a2410a3f0216000be32b013c0ea9; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, 1a160076d3d0dcd4a98a4599ad96eec0790b099b; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, c32df11147822d22facee8fa30c2e8971d12f426; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, 86c9ee928c4a370e323e432aaf8dca79c4ba7c85; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, f5c772b76bbd95de8be51cf849c6098f6af6fcf9; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, dbb500bad02146b388041877574829016591ddc8; e32fd989ac1c45f993fbe89ad0a89aa9ea6993d2 up to, but not including, 1f0bdc2884b67de337215079bba166df0cdf4ac5; and 1 more rangesf1adeb1ff8bef1467d6961059810795d02bbad5d, 99381e762273a2410a3f0216000be32b013c0ea9, 1a160076d3d0dcd4a98a4599ad96eec0790b099b, c32df11147822d22facee8fa30c2e8971d12f426, 86c9ee928c4a370e323e432aaf8dca79c4ba7c85, f5c772b76bbd95de8be51cf849c6098f6af6fcf9
LinuxLinux Kernel5.5 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; 7.25.10.261, 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: usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(), which on a connector-change event calls ucsi_connector_change() and schedules connector work. In ucsi_ccg_remove(), ucsi_destroy() frees uc->ucsi (kfree) before free_irq() is called, so a handler invocation already in flight may access the freed object after ucsi_destroy(). CPU 0 (remove) | CPU 1 (threaded IRQ) ucsi_destroy(uc->ucsi) | ccg_irq_handler() kfree(ucsi) // FREE | ucsi_notify_common(uc->ucsi) // USE Move free_irq() before ucsi_destroy() in the remove path. It is kept after ucsi_unregister(): ucsi_unregister() cancels connector work whose handler issues GET_CONNECTOR_STATUS through ucsi_send_command_common(), which waits for a completion that is signalled from the IRQ handler, so the IRQ must stay active until that work has been cancelled. The probe error path already orders free_irq() before ucsi_destroy(). This bug was found by static analysis.

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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