Linux: Use After Free
CVE-2026-53192 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 38034d04d4a75bbca01df2b313ced0bcd0fa3242, 3d39da65b5c422c5e5afb7d5651b0698d060a827, 306427adf9b97e29e5958cb9cf3096c6151fc9ff 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 0.1% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 38034d04d4a75bbca01df2b313ced0bcd0fa3242 or 3d39da65b5c422c5e5afb7d5651b0698d060a827 or 306427adf9b97e29e5958cb9cf3096c6151fc9ff or 053a401b592be424fea9d57c789f66cd5d8cec11, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.94 or 6.18.36 or 7.0.13, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 37745918e0e7575bc40f38da93a99b9fa6406224 up to, but not including, 38034d04d4a75bbca01df2b313ced0bcd0fa3242; 37745918e0e7575bc40f38da93a99b9fa6406224 up to, but not including, 3d39da65b5c422c5e5afb7d5651b0698d060a827; 37745918e0e7575bc40f38da93a99b9fa6406224 up to, but not including, 306427adf9b97e29e5958cb9cf3096c6151fc9ff; 37745918e0e7575bc40f38da93a99b9fa6406224 up to, but not including, 053a401b592be424fea9d57c789f66cd5d8cec11; 6.12 | 38034d04d4a75bbca01df2b313ced0bcd0fa3242, 3d39da65b5c422c5e5afb7d5651b0698d060a827, 306427adf9b97e29e5958cb9cf3096c6151fc9ff, 053a401b592be424fea9d57c789f66cd5d8cec11 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | all versions | Not stated |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.13; 7.1 | 6.12.94, 6.18.36, 7.0.13 |
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 CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: Fix UAF at snd_timer_user_params() At releasing a timer object, e.g. when a userspace timer (CONFIG_SND_UTIMER) gets closed and snd_timer_free() is called, it tries to detach the timer instances and release the resources. However, it's still possible that other in-flight tasks are holding the timer instance where the to-be-deleted timer object is associated, and this may lead to racy accesses. Fortunately, most of ioctls dealing with the timer instance list already have the protection with register_mutex, and this also avoids such races. But, SNDRV_TIMER_IOCTL_PARAMS isn't protected, hence the concurrent ioctl may lead to use-after-free. This patch just adds the guard with register_mutex to protect snd_timer_user_params() for covering the code path as a quick workaround. It's no hot-path but rather a rarely issued ioctl, so the performance penalty doesn't matter.
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.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use After Free vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 8.2 High severity
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