# 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.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Aug 2026
- **Updated:** 20 Aug 2026
- **Also known as:** GHSA-x3qv-w3hg-xgc7

## 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 (Use After Free)

## Which versions are affected by CVE-2026-49418?

It affects 1 product.


Products: 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.

## 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

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49418 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-49418 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-49418/ (Markdown: https://insights.sbomify.com/CVE-2026-49418/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49418
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49418
- OSV: https://osv.dev/vulnerability/CVE-2026-49418

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49418/
Summaries are generated and may contain mistakes; the official description above is the record.