CyberSecBulletin
CVE-2026-43459NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2026-43459 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists versions bf80a89da97285d9b877e0c6995e870d46b8025c, 3887e514978d28216246360b46a9cb534969eb5a, 231568afbc0cd25b8fb2a94ebf9738eabe1cf007 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 0.15% 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 bf80a89da97285d9b877e0c6995e870d46b8025c or 3887e514978d28216246360b46a9cb534969eb5a or 231568afbc0cd25b8fb2a94ebf9738eabe1cf007 or 317a9298c54bb00319da73e5a7179f00e67fcbdf, 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.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxe894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, bf80a89da97285d9b877e0c6995e870d46b8025c; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, 3887e514978d28216246360b46a9cb534969eb5a; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, 231568afbc0cd25b8fb2a94ebf9738eabe1cf007; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, 317a9298c54bb00319da73e5a7179f00e67fcbdf; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, eab71e11ce2447c1e01809cbc11eab4234cf8dc8; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, 7d33e6140945482a07f8089ee86e13e02553ffdb; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, c054f0607c8bb1b1aa529bc109e4149298a1cccd; e894efef9ac7c10b7727798dcc711cccf07569f9 up to, but not including, 95bc5c225513fc3c4ce169563fb5e3929fbb938b; and 1 more rangesbf80a89da97285d9b877e0c6995e870d46b8025c, 3887e514978d28216246360b46a9cb534969eb5a, 231568afbc0cd25b8fb2a94ebf9738eabe1cf007, 317a9298c54bb00319da73e5a7179f00e67fcbdf, eab71e11ce2447c1e01809cbc11eab4234cf8dc8, 7d33e6140945482a07f8089ee86e13e02553ffdb
LinuxLinux Kernel4.20 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, 6.18.19; 6.19 up to, but not including, 6.19.9; 7.05.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.19

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
RequiredA user must take an action such as opening a file or link.
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:R/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: ASoC: soc-core: flush delayed work before removing DAIs and widgets When a sound card is unbound while a PCM stream is open, a use-after-free can occur in snd_soc_dapm_stream_event(), called from the close_delayed_work workqueue handler. During unbind, snd_soc_unbind_card() flushes delayed work and then calls soc_cleanup_card_resources(). Inside cleanup, snd_card_disconnect_sync() releases all PCM file descriptors, and the resulting PCM close path can call snd_soc_dapm_stream_stop() which schedules new delayed work with a pmdown_time timer delay. Since this happens after the flush in snd_soc_unbind_card(), the new work is not caught. soc_remove_link_components() then frees DAPM widgets before this work fires, leading to the use-after-free. The existing flush in soc_free_pcm_runtime() also cannot help as it runs after soc_remove_link_components() has already freed the widgets. Add a flush in soc_cleanup_card_resources() after snd_card_disconnect_sync() (after which no new PCM closes can schedule further delayed work) and before soc_remove_link_dais() and soc_remove_link_components() (which tear down the structures the delayed work accesses).

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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