CVE-2026-49418
Received
Received - Intake
Kernel Use-After-Free in FreeBSD via msync(MS_INVALIDATE)
Vulnerability report for CVE-2026-49418, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-19
Last updated on: 2026-08-19
Assigner: FreeBSD
Description
Description
When msync(MS_INVALIDATE) is called on a mapping of an unmanaged device object, the physical pages in the mapping range are marked invalid but remain in the pager's page list. A subsequent page fault will cause the fault handler to re-insert the page into the object's list. This corrupts the list, and on object destruction the page is freed twice.
An unprivileged local user with access to a device that provides memory-mapped I/O can trigger a use-after-free in the kernel, though this is limited to a pool of objects ("fictitious pages") that are never recycled for a different purpose. It may be possible to exploit this to escalate privileges.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| freebsd | freebsd | From 2026-06-30 (inc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
