Linux: Double Free
CVE-2026-64447 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 b5ddc7257bee71f5b8cf9083e2b0ac0427e9fbb3, 837c1f9655421055f751ed34745e820a54a27642, d3a9a8cf2d7fd61a2f63df61f6cbc0a9bb007cc0 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 b5ddc7257bee71f5b8cf9083e2b0ac0427e9fbb3 or 837c1f9655421055f751ed34745e820a54a27642 or d3a9a8cf2d7fd61a2f63df61f6cbc0a9bb007cc0, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.39 or 7.1.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b7fe4c0019b12d60ece3e99eeb0ccfd5a1d103e5 up to, but not including, b5ddc7257bee71f5b8cf9083e2b0ac0427e9fbb3; b7fe4c0019b12d60ece3e99eeb0ccfd5a1d103e5 up to, but not including, 837c1f9655421055f751ed34745e820a54a27642; b7fe4c0019b12d60ece3e99eeb0ccfd5a1d103e5 up to, but not including, d3a9a8cf2d7fd61a2f63df61f6cbc0a9bb007cc0; 6.17 | b5ddc7257bee71f5b8cf9083e2b0ac0427e9fbb3, 837c1f9655421055f751ed34745e820a54a27642, d3a9a8cf2d7fd61a2f63df61f6cbc0a9bb007cc0 |
| Linux | Linux Kernel | 6.17 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4 | 6.18.39, 7.1.4 |
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: staging: media: ipu7: fix double-free and use-after-free in error paths In both ipu7_isys_init() and ipu7_psys_init(), pdata is allocated and then passed to ipu7_bus_initialize_device(), which stores it in adev->pdata. The ipu7_bus_release() function frees adev->pdata when the device's reference count drops to zero. Two error paths incorrectly call kfree(pdata) after the device teardown has already freed it: 1. When ipu7_mmu_init() fails: put_device() is called, which drops the reference count to zero and triggers ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is a double-free. 2. When ipu7_bus_add_device() fails: it calls auxiliary_device_uninit() internally, which calls put_device() -> ipu7_bus_release() -> kfree(pdata). The subsequent kfree(pdata) is again a double-free. Note that the kfree(pdata) when ipu7_bus_initialize_device() itself fails is correct, because in that case auxiliary_device_init() failed and the release function was never set up, so pdata must be freed manually. Additionally, the error code was not saved before calling put_device(), causing ERR_CAST() to dereference the already-freed adev pointer when constructing the return value. Fix this by saving the error from dev_err_probe() before put_device() and returning ERR_PTR() instead. Remove the redundant kfree(pdata) calls and fix the use-after-free in the return values of the two affected error paths.
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
Recent Double Free vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
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