Linux: Use After Free
CVE-2026-23227 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 56966a4cfa925ec24edb68ab652a740a7abe2c4d, 9e1ef9396a1899925911b1729cb65665420268df, 92dd1f38d7db75374dcdaf54f1d79d67bffd54e5 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 56966a4cfa925ec24edb68ab652a740a7abe2c4d or 9e1ef9396a1899925911b1729cb65665420268df or 92dd1f38d7db75374dcdaf54f1d79d67bffd54e5 or 1b24d3e8792bcc050c70e8e0dea6b49c4fc63b13, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.77 or 6.18.11 or 6.19.1, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 56966a4cfa925ec24edb68ab652a740a7abe2c4d; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 9e1ef9396a1899925911b1729cb65665420268df; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 92dd1f38d7db75374dcdaf54f1d79d67bffd54e5; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 1b24d3e8792bcc050c70e8e0dea6b49c4fc63b13; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, abfdf449fb3d7b42e85a1ad1c8694b768b1582f4; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 60b75407c172e1f341a8a5097c5cbc97dbbdd893; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 0cd2c155740dbd00868ac5a8ae5d14cd6b9ed385; d3b62dbfc7b9bb013926f56db79b60f6c18c392f up to, but not including, 52b330799e2d6f825ae2bb74662ec1b10eb954bb; and 1 more ranges | 56966a4cfa925ec24edb68ab652a740a7abe2c4d, 9e1ef9396a1899925911b1729cb65665420268df, 92dd1f38d7db75374dcdaf54f1d79d67bffd54e5, 1b24d3e8792bcc050c70e8e0dea6b49c4fc63b13, abfdf449fb3d7b42e85a1ad1c8694b768b1582f4, 60b75407c172e1f341a8a5097c5cbc97dbbdd893 |
| Linux | Linux Kernel | 3.6 up to, but not including, 6.12.77; 6.13 up to, but not including, 6.18.11; 6.19 up to, but not including, 6.19.1 | 6.12.77, 6.18.11, 6.19.1 |
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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/exynos: vidi: use ctx->lock to protect struct vidi_context member variables related to memory alloc/free Exynos Virtual Display driver performs memory alloc/free operations without lock protection, which easily causes concurrency problem. For example, use-after-free can occur in race scenario like this: ``` CPU0 CPU1 CPU2 ---- ---- ---- vidi_connection_ioctl() if (vidi->connection) // true drm_edid = drm_edid_alloc(); // alloc drm_edid ... ctx->raw_edid = drm_edid; ... drm_mode_getconnector() drm_helper_probe_single_connector_modes() vidi_get_modes() if (ctx->raw_edid) // true drm_edid_dup(ctx->raw_edid); if (!drm_edid) // false ... vidi_connection_ioctl() if (vidi->connection) // false drm_edid_free(ctx->raw_edid); // free drm_edid ... drm_edid_alloc(drm_edid->edid) kmemdup(edid); // UAF!! ... ``` To prevent these vulns, at least in vidi_context, member variables related to memory alloc/free should be protected with ctx->lock.
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
Other references
Recent Use After Free vulnerabilities
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