Linux: Use After Free
CVE-2026-45956 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 2987642c5213508c6c9e718324c0d5289a92c474, 65d1213baffa363f2eb1117b1dc7acc573b890f8, 875fa28690e93ed5296c31d3344556c6bb867234 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 2987642c5213508c6c9e718324c0d5289a92c474 or 65d1213baffa363f2eb1117b1dc7acc573b890f8 or 875fa28690e93ed5296c31d3344556c6bb867234 or 21ca24ba51a2c28bcc4df9d7e5a40b0eb66ab76d, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.167 or 6.6.130, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, 2987642c5213508c6c9e718324c0d5289a92c474; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, 65d1213baffa363f2eb1117b1dc7acc573b890f8; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, 875fa28690e93ed5296c31d3344556c6bb867234; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, 21ca24ba51a2c28bcc4df9d7e5a40b0eb66ab76d; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, e1aed617eb80b49eac2f8c7bb7a0990f641dd59b; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, b5fc86d753dd4c281a943b92f0eef02d31af03d7; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, a540f767642f75240a6c35f6a65b69e44cfcea9d; cf67cc9a29ac19c98bc4fa0e6d14b0c1f592d322 up to, but not including, d3968a0d85b211e197f2f4f06268a7031079e0d0; and 1 more ranges | 2987642c5213508c6c9e718324c0d5289a92c474, 65d1213baffa363f2eb1117b1dc7acc573b890f8, 875fa28690e93ed5296c31d3344556c6bb867234, 21ca24ba51a2c28bcc4df9d7e5a40b0eb66ab76d, e1aed617eb80b49eac2f8c7bb7a0990f641dd59b, b5fc86d753dd4c281a943b92f0eef02d31af03d7 |
| Linux | Linux Kernel | 4.3 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, 6.1.167; 6.2 up to, but not including, 6.6.130; 6.7 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4 | 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.18.14, 6.19.4 |
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: drm/exynos: vidi: use priv->vidi_dev for ctx lookup in vidi_connection_ioctl() vidi_connection_ioctl() retrieves the driver_data from drm_dev->dev to obtain a struct vidi_context pointer. However, drm_dev->dev is the exynos-drm master device, and the driver_data contained therein is not the vidi component device, but a completely different device. This can lead to various bugs, ranging from null pointer dereferences and garbage value accesses to, in unlucky cases, out-of-bounds errors, use-after-free errors, and more. To resolve this issue, we need to store/delete the vidi device pointer in exynos_drm_private->vidi_dev during bind/unbind, and then read this exynos_drm_private->vidi_dev within ioctl() to obtain the correct struct vidi_context 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/21ca24ba51a2c28bcc4df9d7e5a40b0eb66ab76d
- git.kernel.org/stable/c/2987642c5213508c6c9e718324c0d5289a92c474
- git.kernel.org/stable/c/65d1213baffa363f2eb1117b1dc7acc573b890f8
- git.kernel.org/stable/c/875fa28690e93ed5296c31d3344556c6bb867234
- git.kernel.org/stable/c/a540f767642f75240a6c35f6a65b69e44cfcea9d
- git.kernel.org/stable/c/b5fc86d753dd4c281a943b92f0eef02d31af03d7
- git.kernel.org/stable/c/d3968a0d85b211e197f2f4f06268a7031079e0d0
Other references
Recent Use After Free vulnerabilities
- 8.1 High 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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