CyberSecBulletin
CVE-2026-31578NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-31578 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 0d36653a3a821e5a974798adb347b3ea09332914, 25d500cf391e384356a612b85cf60b353ad3cd0c, 07ceb444c8f627cf863864d4274b5a77769725ed 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 0d36653a3a821e5a974798adb347b3ea09332914 or 25d500cf391e384356a612b85cf60b353ad3cd0c or 07ceb444c8f627cf863864d4274b5a77769725ed or cb8092038e95dc1113a68e63762de40fff61ba71, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.136 or 6.12.83 or 6.18.24 or 6.19.14, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxcd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 0d36653a3a821e5a974798adb347b3ea09332914; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 25d500cf391e384356a612b85cf60b353ad3cd0c; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 07ceb444c8f627cf863864d4274b5a77769725ed; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, cb8092038e95dc1113a68e63762de40fff61ba71; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 582fbecb3756330006fe1950762412a68c2cacd2; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 09e9206008b887aa553733bd915d73131071a086; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 2eeae47a438694408189138048a786be99954032; cd19f7d3e39b3160595d56bb3e3a2bf4f7f4669c up to, but not including, 7e5aedf6059cba2a669d86caeaf5a51f33ec85a1; and 2 more ranges0d36653a3a821e5a974798adb347b3ea09332914, 25d500cf391e384356a612b85cf60b353ad3cd0c, 07ceb444c8f627cf863864d4274b5a77769725ed, cb8092038e95dc1113a68e63762de40fff61ba71, 582fbecb3756330006fe1950762412a68c2cacd2, 09e9206008b887aa553733bd915d73131071a086
LinuxLinux Kernelbefore 6.6.136; 6.7 up to, but not including, 6.12.83; 6.13 up to, but not including, 6.18.24; 6.19 up to, but not including, 6.19.14; 7.0 up to, but not including, 7.0.16.6.136, 6.12.83, 6.18.24, 6.19.14, 7.0.1

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: media: as102: fix to not free memory after the device is registered in as102_usb_probe() In as102_usb driver, the following race condition occurs: ``` CPU0 CPU1 as102_usb_probe() kzalloc(); // alloc as102_dev_t .... usb_register_dev(); fd = sys_open("/path/to/dev"); // open as102 fd .... usb_deregister_dev(); .... kfree(); // free as102_dev_t .... sys_close(fd); as102_release() // UAF!! as102_usb_release() kfree(); // DFB!! ``` When a USB character device registered with usb_register_dev() is later unregistered (via usb_deregister_dev() or disconnect), the device node is removed so new open() calls fail. However, file descriptors that are already open do not go away immediately: they remain valid until the last reference is dropped and the driver's .release() is invoked. In as102, as102_usb_probe() calls usb_register_dev() and then, on an error path, does usb_deregister_dev() and frees as102_dev_t right away. If userspace raced a successful open() before the deregistration, that open FD will later hit as102_release() --> as102_usb_release() and access or free as102_dev_t again, occur a race to use-after-free and double-free vuln. The fix is to never kfree(as102_dev_t) directly once usb_register_dev() has succeeded. After deregistration, defer freeing memory to .release(). In other words, let release() perform the last kfree when the final open FD is closed.

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

Spotted an error? Tell us.