Linux: Use After Free
CVE-2026-31582 is a high-severity use after 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 c78e1d4e48f23792adaa7c94251e22b0d9700a39, 9e1b798257f96d2e2a2639830eb71add545ce749, 7003ae4810ca83f0ddca85b768500e313c4b998c 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 c78e1d4e48f23792adaa7c94251e22b0d9700a39 or 9e1b798257f96d2e2a2639830eb71add545ce749 or 7003ae4810ca83f0ddca85b768500e313c4b998c or 61f2aa23b0ce8d7aa5071ed25a7471e246a4fdd4, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.83 or 6.18.24 or 6.19.14 or 7.0.1, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 4381a36abdf1c5c0323c1c51f869dc000115eb20 up to, but not including, c78e1d4e48f23792adaa7c94251e22b0d9700a39; 4381a36abdf1c5c0323c1c51f869dc000115eb20 up to, but not including, 9e1b798257f96d2e2a2639830eb71add545ce749; 4381a36abdf1c5c0323c1c51f869dc000115eb20 up to, but not including, 7003ae4810ca83f0ddca85b768500e313c4b998c; 4381a36abdf1c5c0323c1c51f869dc000115eb20 up to, but not including, 61f2aa23b0ce8d7aa5071ed25a7471e246a4fdd4; 4381a36abdf1c5c0323c1c51f869dc000115eb20 up to, but not including, 08e57f5e1a9067d5fbf33993aa7f51d60b3d13a4; 6.7 | c78e1d4e48f23792adaa7c94251e22b0d9700a39, 9e1b798257f96d2e2a2639830eb71add545ce749, 7003ae4810ca83f0ddca85b768500e313c4b998c, 61f2aa23b0ce8d7aa5071ed25a7471e246a4fdd4, 08e57f5e1a9067d5fbf33993aa7f51d60b3d13a4 |
| Linux | Linux Kernel | before 6.12.83; 6.13 up to, but not including, 6.18.24; 6.19 up to, but not including, 6.19.14; 7.0 up to, but not including, 7.0.1 | 6.12.83, 6.18.24, 6.19.14, 7.0.1 |
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: hwmon: (powerz) Fix use-after-free on USB disconnect After powerz_disconnect() frees the URB and releases the mutex, a subsequent powerz_read() call can acquire the mutex and call powerz_read_data(), which dereferences the freed URB pointer. Fix by: - Setting priv->urb to NULL in powerz_disconnect() so that powerz_read_data() can detect the disconnected state. - Adding a !priv->urb check at the start of powerz_read_data() to return -ENODEV on a disconnected device. - Moving usb_set_intfdata() before hwmon registration so the disconnect handler can always find the priv pointer.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/08e57f5e1a9067d5fbf33993aa7f51d60b3d13a4
- git.kernel.org/stable/c/61f2aa23b0ce8d7aa5071ed25a7471e246a4fdd4
- git.kernel.org/stable/c/7003ae4810ca83f0ddca85b768500e313c4b998c
- git.kernel.org/stable/c/9e1b798257f96d2e2a2639830eb71add545ce749
- git.kernel.org/stable/c/c78e1d4e48f23792adaa7c94251e22b0d9700a39
Recent Use After 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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