# CVE-2026-98229: xfrm: save input state data before secpath resets

> A use-after-free in the Linux kernel xfrm subsystem allows attackers to cause denial of service or execute code via crafted network packets.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106053, BELL-CVE-2026-98229, DEBIAN-CVE-2026-98229, GHSA-cfrr-f5xv-fcq4, UBUNTU-CVE-2026-98229

## What is CVE-2026-98229?

CVE-2026-98229 is a high-severity use after free vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

xfrm: save input state data before secpath resets

xfrm_input() stores the current xfrm_state in the skb secpath while it
continues receive-side processing. Some input paths can reset that secpath
before xfrm_input() has finished dereferencing the state.

Receive callback users such as VTI and XFRM interfaces can reset the
secpath. The VTI receive path does so before checking whether the packet
crosses network namespaces, while the XFRM interface path does so only for
cross-network-namespace packets. The XFRM_MAX_DEPTH error path can also
reset the secpath before the final drop callback reports the current
state's protocol.

If secpath_reset() drops the last state reference while the state is
concurrently deleted, xfrm_input() can still dereference the freed state
when selecting transport_finish() or reporting the drop callback protocol.

Save the state protocol on the stack while the state is still valid,
and use the already saved address family for transport_finish(). A larval
XFRM_STATE_ACQ state has no type, so retain nexthdr as its protocol. This
preserves the existing drop-path fallback while avoiding the post-reset
state dereferences without adding an extra state reference to every
received packet.

## Which versions are affected by CVE-2026-98229?


## How do I fix CVE-2026-98229?

Apply the vendor's patch.

## Is CVE-2026-98229 being exploited?

There is no known exploitation of CVE-2026-98229 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98229 and fix it if it is affected.

What it is: CVE-2026-98229 is a high-severity use after free vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-98229 in the wild and no public exploit code.

Affected product: Linux. 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-2026-98229/ (Markdown: https://insights.sbomify.com/CVE-2026-98229/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98229
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98229
- OSV: https://osv.dev/vulnerability/CVE-2026-98229

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98229/
Summaries are generated and may contain mistakes; the official description above is the record.