CyberSecBulletin
CVE-2026-46047NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-46047 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 65168712c216584ff482a7d1a67589f2079b2634, dff081c3602f2fd810f69ef47945a226980dd05d, 4ae0bd51bf7079e9c2a06b5de0ae04ba70d10167 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 65168712c216584ff482a7d1a67589f2079b2634 or dff081c3602f2fd810f69ef47945a226980dd05d or 4ae0bd51bf7079e9c2a06b5de0ae04ba70d10167 or 0f313eb6a8f6dffa491373cf3afab979fa1c02f4, 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.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, 65168712c216584ff482a7d1a67589f2079b2634; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, dff081c3602f2fd810f69ef47945a226980dd05d; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, 4ae0bd51bf7079e9c2a06b5de0ae04ba70d10167; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, 0f313eb6a8f6dffa491373cf3afab979fa1c02f4; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, db3c60ec772de30acae92d560dfcc5258e58dbe8; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, 2e127ceb1c415e246076d8e09e23e443a7a2038f; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, f96779e916576e81430ebb326baff6e433fef8ae; 0c2204a4ad710d95d348ea006f14ba926e842ffd up to, but not including, 7809fea20c9404bfcfa6112ec08d1fe1d3520beb; and 1 more ranges65168712c216584ff482a7d1a67589f2079b2634, dff081c3602f2fd810f69ef47945a226980dd05d, 4ae0bd51bf7079e9c2a06b5de0ae04ba70d10167, 0f313eb6a8f6dffa491373cf3afab979fa1c02f4, db3c60ec772de30acae92d560dfcc5258e58dbe8, 2e127ceb1c415e246076d8e09e23e443a7a2038f
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel5.7 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, 6.12.86; 6.13 up to, but not including, 6.18.27; 6.19 up to, but not including, 7.0.45.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27

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: net: qrtr: ns: Fix use-after-free in driver remove() In the remove callback, if a packet arrives after destroy_workqueue() is called, but before sock_release(), the qrtr_ns_data_ready() callback will try to queue the work, causing use-after-free issue. Fix this issue by saving the default 'sk_data_ready' callback during qrtr_ns_init() and use it to replace the qrtr_ns_data_ready() callback at the start of remove(). This ensures that even if a packet arrives after destroy_workqueue(), the work struct will not be dereferenced. Note that it is also required to ensure that the RX threads are completed before destroying the workqueue, because the threads could be using the qrtr_ns_data_ready() callback.

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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