Linux: Use After Free
CVE-2026-46240 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 dd24998a4a4016fb9921916024399bd80f0d45c6, 18c64439f249859b6140f7bf8bcf95c8ed841f28, f27cfdcfc916bb59297825805f4c3499f89f9e76 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 0.12% 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 dd24998a4a4016fb9921916024399bd80f0d45c6 or 18c64439f249859b6140f7bf8bcf95c8ed841f28 or f27cfdcfc916bb59297825805f4c3499f89f9e76 or 6.18.32, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.32 or 7.0.9, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7cde76db8883ec8a3d1456068079ecadbfb15ca5 up to, but not including, dd24998a4a4016fb9921916024399bd80f0d45c6; 1dabf00ee206eceb0f08a1fe5d1ce635f9064338 up to, but not including, 18c64439f249859b6140f7bf8bcf95c8ed841f28; 1dabf00ee206eceb0f08a1fe5d1ce635f9064338 up to, but not including, f27cfdcfc916bb59297825805f4c3499f89f9e76; d4457f23ac0130240053a34be663f0fade3bb371; 6.18.16 up to, but not including, 6.18.32; 6.19.6 up to, but not including, 6.20; 7.0 | dd24998a4a4016fb9921916024399bd80f0d45c6, 18c64439f249859b6140f7bf8bcf95c8ed841f28, f27cfdcfc916bb59297825805f4c3499f89f9e76, 6.18.32, 6.20 |
| Linux | Linux Kernel | 6.18.16 up to, but not including, 6.18.32; 6.19.6 up to, but not including, 7.0.9; 7.1 | 6.18.32, 7.0.9 |
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: media: iris: Fix use-after-free in iris_release_internal_buffers() The recent change in commit 1dabf00ee206 ("media: iris: gen1: Destroy internal buffers after FW releases") introduced a regression where session_release_buf() may free the buffer. The caller, iris_release_internal_buffers(), continued to access `buffer` after the call, leading to a potential use-after-free. Fix this by setting BUF_ATTR_PENDING_RELEASE before calling session_release_buf(), and reverting the flag if the call fails. This ensures no dereference occurs after potential freeing.
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
Recent Use After Free vulnerabilities
- 8.3 High severity
- 8.8 High severity
- 8.3 High severity
- 8.3 High severity
- 8.8 High severity
- 7.5 High severity
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