Linux: Double Free
CVE-2026-31489 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 01f5f7976c24d6e9beef6b5a410af3b9b1d4d476, d61bcec3aec6f0244a9b963e0c76c00f771d49b6, 7434c64ddae88a02e7fb478bc256cc100d48d3e3 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 01f5f7976c24d6e9beef6b5a410af3b9b1d4d476 or d61bcec3aec6f0244a9b963e0c76c00f771d49b6 or 7434c64ddae88a02e7fb478bc256cc100d48d3e3 or 0d645c6d13fa0597935d3d16b09a7ba5d24ed284, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.15 or 4.20 or 5.5 or 5.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 05565b469358a9a03034f7f712d83590a9f125a4 up to, but not including, 01f5f7976c24d6e9beef6b5a410af3b9b1d4d476; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, d61bcec3aec6f0244a9b963e0c76c00f771d49b6; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, 7434c64ddae88a02e7fb478bc256cc100d48d3e3; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, 0d645c6d13fa0597935d3d16b09a7ba5d24ed284; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, 40ad0334c17b23d8b66b1082ad1478a6202e90e2; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, da06a104f0486355073ff0d1bcb1fcbebb7080d6; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, 9b812ceb75a6260c17c91db4b9e74ead8cfa06f5; 8311ee2164c5cd1b63a601ea366f540eae89f10e up to, but not including, 63542bb402b7013171c9f621c28b609eda4dbf1f; and 10 more ranges | 01f5f7976c24d6e9beef6b5a410af3b9b1d4d476, d61bcec3aec6f0244a9b963e0c76c00f771d49b6, 7434c64ddae88a02e7fb478bc256cc100d48d3e3, 0d645c6d13fa0597935d3d16b09a7ba5d24ed284, 40ad0334c17b23d8b66b1082ad1478a6202e90e2, da06a104f0486355073ff0d1bcb1fcbebb7080d6 |
| Linux | Linux Kernel | 4.14.244 up to, but not including, 4.15; 4.19.203 up to, but not including, 4.20; 5.4.140 up to, but not including, 5.5; 5.10.58 up to, but not including, 5.11; 5.13.10 up to, but not including, 5.14; 5.14.1 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; and 2 more ranges | 4.15, 4.20, 5.5, 5.11, 5.14, 6.12.80 |
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: spi: meson-spicc: Fix double-put in remove path meson_spicc_probe() registers the controller with devm_spi_register_controller(), so teardown already drops the controller reference via devm cleanup. Calling spi_controller_put() again in meson_spicc_remove() causes a double-put.
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
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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