Linux: Use After Free
CVE-2026-31583 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 3c0283a59e36e3707c4a81f4952e362d31f876b8, 2cbf81f76842e46bdf25823c70e1db4044a65678, 38a327221f7f765e7d853b7bafe47e342441ec85 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.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 3c0283a59e36e3707c4a81f4952e362d31f876b8 or 2cbf81f76842e46bdf25823c70e1db4044a65678 or 38a327221f7f765e7d853b7bafe47e342441ec85 or b5d141ea15f173f15b9f0a72965902f3428c0d92, whichever matches your release line, or a later version.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 3c0283a59e36e3707c4a81f4952e362d31f876b8; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 2cbf81f76842e46bdf25823c70e1db4044a65678; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 38a327221f7f765e7d853b7bafe47e342441ec85; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, b5d141ea15f173f15b9f0a72965902f3428c0d92; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 5fb2940327722b4684d2f964b54c1c90aa277324; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 871b8ea8ef39a6c253594649f4339378fad3d0dd; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, 6b9e66437cc6123ddedac141e1b8b6fcf57d2972; 8139a4d583abad45eb987b5a99b3281b6d435b7e up to, but not including, dd2b888e08d3b3d6aacd65d76cd44fac11da750f; and 2 more ranges | 3c0283a59e36e3707c4a81f4952e362d31f876b8, 2cbf81f76842e46bdf25823c70e1db4044a65678, 38a327221f7f765e7d853b7bafe47e342441ec85, b5d141ea15f173f15b9f0a72965902f3428c0d92, 5fb2940327722b4684d2f964b54c1c90aa277324, 871b8ea8ef39a6c253594649f4339378fad3d0dd |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | all versions | Not stated |
| Linux | Linux Kernel | before 6.6.136; 6.12 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, 7.0.1 | 6.6.136, 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: em28xx: fix use-after-free in em28xx_v4l2_open() em28xx_v4l2_open() reads dev->v4l2 without holding dev->lock, creating a race with em28xx_v4l2_init()'s error path and em28xx_v4l2_fini(), both of which free the em28xx_v4l2 struct and set dev->v4l2 to NULL under dev->lock. This race leads to two issues: - use-after-free in v4l2_fh_init() when accessing vdev->ctrl_handler, since the video_device is embedded in the freed em28xx_v4l2 struct. - NULL pointer dereference in em28xx_resolution_set() when accessing v4l2->norm, since dev->v4l2 has been set to NULL. Fix this by moving the mutex_lock() before the dev->v4l2 read and adding a NULL check for dev->v4l2 under the lock.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/5fb2940327722b4684d2f964b54c1c90aa277324
- git.kernel.org/stable/c/6b9e66437cc6123ddedac141e1b8b6fcf57d2972
- git.kernel.org/stable/c/871b8ea8ef39a6c253594649f4339378fad3d0dd
- git.kernel.org/stable/c/a66485a934c7187ae8e36517d40615fa2e961cff
- git.kernel.org/stable/c/b5d141ea15f173f15b9f0a72965902f3428c0d92
- git.kernel.org/stable/c/dd2b888e08d3b3d6aacd65d76cd44fac11da750f
Other references
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.