Linux: Double Free
CVE-2026-46129 is a high-severity double 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 ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5, c2670ec4aa49ca226bce9776601e0da37502be07, f414b3abbba59ef379a2b3c31f2bdd9358ed5e53 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 0.14% 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 ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5 or c2670ec4aa49ca226bce9776601e0da37502be07 or f414b3abbba59ef379a2b3c31f2bdd9358ed5e53 or 9a060970fd7b5e1c561e4ce73cb9949e4269a738, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.175 or 6.6.140 or 6.12.88 or 6.18.30, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 20e8f2de3688082eeafeb93c8900485b7542457e up to, but not including, ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5; 58208907c4044a764dbd8896026283905da6d9be up to, but not including, c2670ec4aa49ca226bce9776601e0da37502be07; bb4fa4c0b54aae25e55faeda7f78d0c11b8cd618 up to, but not including, f414b3abbba59ef379a2b3c31f2bdd9358ed5e53; 6cb008f1bb23e023dfe615cca5df14570dfc8da5 up to, but not including, 9a060970fd7b5e1c561e4ce73cb9949e4269a738; a11224a016d6d1d46a4d9b6573244448a80d4d7f up to, but not including, dd6ade0fdd59218d71a981ae7c937a304e49209c; a11224a016d6d1d46a4d9b6573244448a80d4d7f up to, but not including, 3f487be81292702a59ea9dbc4088b3360a50e837; 6.1.162 up to, but not including, 6.1.175; 6.6.122 up to, but not including, 6.6.140; and 3 more ranges | ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5, c2670ec4aa49ca226bce9776601e0da37502be07, f414b3abbba59ef379a2b3c31f2bdd9358ed5e53, 9a060970fd7b5e1c561e4ce73cb9949e4269a738, dd6ade0fdd59218d71a981ae7c937a304e49209c, 3f487be81292702a59ea9dbc4088b3360a50e837 |
| Linux | Linux Kernel | 6.1.162 up to, but not including, 6.1.175; 6.6.122 up to, but not including, 6.6.140; 6.12.67 up to, but not including, 6.12.88; 6.18.7 up to, but not including, 6.18.30; 6.19.1 up to, but not including, 7.0.7; 6.19 | 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7 |
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: btrfs: fix double free in create_space_info() error path When kobject_init_and_add() fails, the call chain is: create_space_info() -> btrfs_sysfs_add_space_info_type() -> kobject_init_and_add() -> failure -> kobject_put(&space_info->kobj) -> space_info_release() -> kfree(space_info) Then control returns to create_space_info(): btrfs_sysfs_add_space_info_type() returns error -> goto out_free -> kfree(space_info) This causes a double free. Keep the direct kfree(space_info) for the earlier failure path, but after btrfs_sysfs_add_space_info_type() has called kobject_put(), let the kobject release callback handle the cleanup.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/3f487be81292702a59ea9dbc4088b3360a50e837
- git.kernel.org/stable/c/9a060970fd7b5e1c561e4ce73cb9949e4269a738
- git.kernel.org/stable/c/ae6d6e31ceb72b7697c28a528e4923c08e3c2ef5
- git.kernel.org/stable/c/c2670ec4aa49ca226bce9776601e0da37502be07
- git.kernel.org/stable/c/dd6ade0fdd59218d71a981ae7c937a304e49209c
- git.kernel.org/stable/c/f414b3abbba59ef379a2b3c31f2bdd9358ed5e53
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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