Linux: Double Free
CVE-2026-31759 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 2f70ba9dae13a190673cc3f9b4aad52179738f60, ee248e6e941e4f2e634df2bd43e5f1ef810ab6df, 272a9b26c336a295e4e209157fed809706c1b1f7 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 2f70ba9dae13a190673cc3f9b4aad52179738f60 or ee248e6e941e4f2e634df2bd43e5f1ef810ab6df or 272a9b26c336a295e4e209157fed809706c1b1f7 or aaeae6533d77e6ed4def85baec01e2815ebbef61, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.134, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, 2f70ba9dae13a190673cc3f9b4aad52179738f60; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, ee248e6e941e4f2e634df2bd43e5f1ef810ab6df; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, 272a9b26c336a295e4e209157fed809706c1b1f7; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, aaeae6533d77e6ed4def85baec01e2815ebbef61; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, 8763f8317bb389aded32a32b08f6751cfff657d2; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, 38c28fe25611099230f0965c925499bfcf46a795; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, a6e5461f076c2ef63159f18e5cdbd30b50f0bc15; 289fcff4bcdb1dcc0ce8788b7ea0f58a9e4a495f up to, but not including, 01af542392b5d41fd659d487015a71f627accce3; and 1 more ranges | 2f70ba9dae13a190673cc3f9b4aad52179738f60, ee248e6e941e4f2e634df2bd43e5f1ef810ab6df, 272a9b26c336a295e4e209157fed809706c1b1f7, aaeae6533d77e6ed4def85baec01e2815ebbef61, 8763f8317bb389aded32a32b08f6751cfff657d2, 38c28fe25611099230f0965c925499bfcf46a795 |
| Linux | Linux Kernel | 4.2 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.134; 6.7 up to, but not including, 6.12.81; 6.13 up to, but not including, 6.18.22; 6.19 up to, but not including, 6.19.12; 7.0 | 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22 |
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: usb: ulpi: fix double free in ulpi_register_interface() error path When device_register() fails, ulpi_register() calls put_device() on ulpi->dev. The device release callback ulpi_dev_release() drops the OF node reference and frees ulpi, but the current error path in ulpi_register_interface() then calls kfree(ulpi) again, causing a double free. Let put_device() handle the cleanup through ulpi_dev_release() and avoid freeing ulpi again in ulpi_register_interface().
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/01af542392b5d41fd659d487015a71f627accce3
- git.kernel.org/stable/c/272a9b26c336a295e4e209157fed809706c1b1f7
- git.kernel.org/stable/c/2f70ba9dae13a190673cc3f9b4aad52179738f60
- git.kernel.org/stable/c/38c28fe25611099230f0965c925499bfcf46a795
- git.kernel.org/stable/c/8763f8317bb389aded32a32b08f6751cfff657d2
- git.kernel.org/stable/c/a6e5461f076c2ef63159f18e5cdbd30b50f0bc15
- git.kernel.org/stable/c/aaeae6533d77e6ed4def85baec01e2815ebbef61
- git.kernel.org/stable/c/ee248e6e941e4f2e634df2bd43e5f1ef810ab6df
Recent Double Free vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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