CVE-2026-49418 Use-after-free in device pager page list
A use-after-free in the FreeBSD kernel device pager allows local users to potentially escalate privileges via memory-mapped I/O.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-49418?
CVE-2026-49418 is a high-severity use after free vulnerability in Freebsd Freebsd, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2026-49418?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-49418?
No fix has been published for CVE-2026-49418 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-49418 being exploited?
There is no known exploitation of CVE-2026-49418 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-x3qv-w3hg-xgc7.