CVE-2026-46129 btrfs: fix double free in create_space_info() error path
A double free vulnerability in the Linux kernel's btrfs filesystem allows attackers to potentially execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46129?
CVE-2026-46129 is a high-severity use after free vulnerability in Linux kernel, published on 28 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-415
Which versions are affected by CVE-2026-46129?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46129?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-46129 being exploited?
There is no known exploitation of CVE-2026-46129 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-89088, BELL-CVE-2026-46129, DEBIAN-CVE-2026-46129, GHSA-4m7v-4fw7-9hch, ROOT-OS-DEBIAN-12-CVE-2026-46129, ROOT-OS-UBUNTU-2404-CVE-2026-46129 and 1 more.