Linux: Use After Free
CVE-2026-53024 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 5a6ce05ccd9eca653b09d67eb59026821ffaf61b, 966b941ca469fb794637a0803670454f68515e40, 2b46f07913a80521ecfe60b229c84bdd7dfb15ab 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 0.17% 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 5a6ce05ccd9eca653b09d67eb59026821ffaf61b or 966b941ca469fb794637a0803670454f68515e40 or 2b46f07913a80521ecfe60b229c84bdd7dfb15ab or 48d6c32bc049abd114e8f0836c0e7d7cbfba7827, whichever matches your release line, or a later version.
- Update Linux Kernel to 7.0.10 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | e806c7fb8e9bae87fc23958c3789f2c2f96f54a4 up to, but not including, 5a6ce05ccd9eca653b09d67eb59026821ffaf61b; e806c7fb8e9bae87fc23958c3789f2c2f96f54a4 up to, but not including, 966b941ca469fb794637a0803670454f68515e40; e806c7fb8e9bae87fc23958c3789f2c2f96f54a4 up to, but not including, 2b46f07913a80521ecfe60b229c84bdd7dfb15ab; e806c7fb8e9bae87fc23958c3789f2c2f96f54a4 up to, but not including, 48d6c32bc049abd114e8f0836c0e7d7cbfba7827; e806c7fb8e9bae87fc23958c3789f2c2f96f54a4 up to, but not including, 84265cbd96b97058ef67e3f8be3933667a000835; 4.9 | 5a6ce05ccd9eca653b09d67eb59026821ffaf61b, 966b941ca469fb794637a0803670454f68515e40, 2b46f07913a80521ecfe60b229c84bdd7dfb15ab, 48d6c32bc049abd114e8f0836c0e7d7cbfba7827, 84265cbd96b97058ef67e3f8be3933667a000835 |
| Linux | Linux Kernel | 4.9 up to, but not including, 7.0.10 | 7.0.10 |
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: greybus: raw: fix use-after-free if write is called after disconnect If a user writes to the chardev after disconnect has been called, the kernel panics with the following trace (with CONFIG_INIT_ON_FREE_DEFAULT_ON=y): BUG: kernel NULL pointer dereference, address: 0000000000000218 ... Call Trace: <TASK> gb_operation_create_common+0x61/0x180 gb_operation_create_flags+0x28/0xa0 gb_operation_sync_timeout+0x6f/0x100 raw_write+0x7b/0xc7 [gb_raw] vfs_write+0xcf/0x420 ? task_mm_cid_work+0x136/0x220 ksys_write+0x63/0xe0 do_syscall_64+0xa4/0x290 entry_SYSCALL_64_after_hwframe+0x77/0x7f Disconnect calls gb_connection_destroy, which ends up freeing the connection object. When gb_operation_sync is called in the write file operations, its gets a freed connection as parameter and the kernel panics. The gb_connection_destroy cannot be moved out of the disconnect function, as the Greybus subsystem expect all connections belonging to a bundle to be destroyed when disconnect returns. To prevent this bug, use a rw lock to synchronize access between write and disconnect. This guarantees that the write function doesn't try to use a disconnected connection.
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.
- 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
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
- 9.6 Critical severity
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