# CVE-2026-46244: netfilter: nft_inner: Fix IPv6 inner_thoff desync

> A logic error in Linux kernel netfilter allows attackers to bypass firewall rules by forging transport headers in inner IPv6 packets.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-89357, BELL-CVE-2026-46244, DEBIAN-CVE-2026-46244, GHSA-fgx8-r5g7-5cr9, ROOT-OS-DEBIAN-13-CVE-2026-46244, ROOT-OS-UBUNTU-2404-CVE-2026-46244, UBUNTU-CVE-2026-46244

## What is CVE-2026-46244?

CVE-2026-46244 is a critical vulnerability in Linux kernel, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

netfilter: nft_inner: Fix IPv6 inner_thoff desync

In nft_inner_parse_l2l3(), when processing inner IPv6 packets,
ipv6_find_hdr() correctly computes the transport header offset
traversing all extension headers, but the result is immediately
overwritten with nhoff + sizeof(_ip6h) (40 bytes), which only
accounts for the IPv6 base header. This creates a desync between
inner_thoff (wrong — points to extension header start) and l4proto
(correct — e.g., IPPROTO_TCP), enabling transport header forgery
and potential firewall bypass. This issue affects stable versions
from Linux 6.2.

For comparison, the normal (non-inner) IPv6 path correctly
preserves ipv6_find_hdr()'s result. Removing the incorrect overwrite
ensures that ipv6_find_hdr()'s calculated transport header offset is
preserved, thereby fixing the desynchronization.

Weakness: CWE-823 (Use of Out-of-range Pointer Offset), CWE-682 (Incorrect Calculation)

## Which versions are affected by CVE-2026-46244?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46244?

Apply the vendor's patch.

## Is CVE-2026-46244 being exploited?

There is no known exploitation of CVE-2026-46244 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-46244 and fix it if it is affected.

What it is: CVE-2026-46244 is a critical vulnerability in Linux kernel, published on 3 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-46244 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-46244/ (Markdown: https://insights.sbomify.com/CVE-2026-46244/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46244
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46244
- OSV: https://osv.dev/vulnerability/CVE-2026-46244

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46244/
Summaries are generated and may contain mistakes; the official description above is the record.