# CVE-2026-23103: ipvlan: Make the addrs_lock be per port

> A race condition in the Linux kernel ipvlan driver could cause false-negative address checks or inconsistent state during IPv6 address changes.

- **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:** 4 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-77283, BELL-CVE-2026-23103, DEBIAN-CVE-2026-23103, GHSA-ghmm-m363-9645, ROOT-OS-DEBIAN-11-CVE-2026-23103, ROOT-OS-DEBIAN-12-CVE-2026-23103, ROOT-OS-DEBIAN-13-CVE-2026-23103, ROOT-OS-UBUNTU-2204-CVE-2026-23103, ROOT-OS-UBUNTU-2404-CVE-2026-23103, UBUNTU-CVE-2026-23103

## What is CVE-2026-23103?

CVE-2026-23103 is a high-severity vulnerability in Linux kernel, published on 4 Feb 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:

ipvlan: Make the addrs_lock be per port

Make the addrs_lock be per port, not per ipvlan dev.

Initial code seems to be written in the assumption,
that any address change must occur under RTNL.
But it is not so for the case of IPv6. So

1) Introduce per-port addrs_lock.

2) It was needed to fix places where it was forgotten
to take lock (ipvlan_open/ipvlan_close)

This appears to be a very minor problem though.
Since it's highly unlikely that ipvlan_add_addr() will
be called on 2 CPU simultaneously. But nevertheless,
this could cause:

1) False-negative of ipvlan_addr_busy(): one interface
iterated through all port->ipvlans + ipvlan->addrs
under some ipvlan spinlock, and another added IP
under its own lock. Though this is only possible
for IPv6, since looks like only ipvlan_addr6_event() can be
called without rtnl_lock.

2) Race since ipvlan_ht_addr_add(port) is called under
different ipvlan->addrs_lock locks

This should not affect performance, since add/remove IP
is a rare situation and spinlock is not taken on fast
paths.

Weakness: CWE-667 (Improper Locking), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-23103?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23103?

Apply the vendor's patch.

## Is CVE-2026-23103 being exploited?

There is no known exploitation of CVE-2026-23103 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-2026-23103 and fix it if it is affected.

What it is: CVE-2026-23103 is a high-severity vulnerability in Linux kernel, published on 4 Feb 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-2026-23103 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-2026-23103/ (Markdown: https://insights.sbomify.com/CVE-2026-23103/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23103
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23103
- OSV: https://osv.dev/vulnerability/CVE-2026-23103

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23103/
Summaries are generated and may contain mistakes; the official description above is the record.