# CVE-2025-38146: net: openvswitch: Fix the dead loop of MPLS parse

> A remote attacker can cause a denial of service via a dead loop in the Linux kernel's Open vSwitch MPLS parser.

- **Severity:** Critical 9.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Jul 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-64487, BELL-CVE-2025-38146, DEBIAN-CVE-2025-38146, GHSA-28ww-ch52-w98x, ROOT-OS-DEBIAN-11-CVE-2025-38146, ROOT-OS-DEBIAN-12-CVE-2025-38146, ROOT-OS-UBUNTU-2204-CVE-2025-38146, ROOT-OS-UBUNTU-2404-CVE-2025-38146, UBUNTU-CVE-2025-38146

## What is CVE-2025-38146?

CVE-2025-38146 is a critical denial of service vulnerability in Debian Debian Linux, published on 3 Jul 2025. 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:

net: openvswitch: Fix the dead loop of MPLS parse

The unexpected MPLS packet may not end with the bottom label stack.
When there are many stacks, The label count value has wrapped around.
A dead loop occurs, soft lockup/CPU stuck finally.

stack backtrace:
UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26
index -1 is out of range for type '__be32 [3]'
CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G           OE   5.15.0-121-generic #131-Ubuntu
Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021
Call Trace:
 <IRQ>
 show_stack+0x52/0x5c
 dump_stack_lvl+0x4a/0x63
 dump_stack+0x10/0x16
 ubsan_epilogue+0x9/0x36
 __ubsan_handle_out_of_bounds.cold+0x44/0x49
 key_extract_l3l4+0x82a/0x840 [openvswitch]
 ? kfree_skbmem+0x52/0xa0
 key_extract+0x9c/0x2b0 [openvswitch]
 ovs_flow_key_extract+0x124/0x350 [openvswitch]
 ovs_vport_receive+0x61/0xd0 [openvswitch]
 ? kernel_init_free_pages.part.0+0x4a/0x70
 ? get_page_from_freelist+0x353/0x540
 netdev_port_receive+0xc4/0x180 [openvswitch]
 ? netdev_port_receive+0x180/0x180 [openvswitch]
 netdev_frame_hook+0x1f/0x40 [openvswitch]
 __netif_receive_skb_core.constprop.0+0x23a/0xf00
 __netif_receive_skb_list_core+0xfa/0x240
 netif_receive_skb_list_internal+0x18e/0x2a0
 napi_complete_done+0x7a/0x1c0
 bnxt_poll+0x155/0x1c0 [bnxt_en]
 __napi_poll+0x30/0x180
 net_rx_action+0x126/0x280
 ? bnxt_msix+0x67/0x80 [bnxt_en]
 handle_softirqs+0xda/0x2d0
 irq_exit_rcu+0x96/0xc0
 common_interrupt+0x8e/0xa0
 </IRQ>

Weakness: CWE-129 (Improper Validation of Array Index)

## Which versions are affected by CVE-2025-38146?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38146?

Apply the vendor's patch.

## Is CVE-2025-38146 being exploited?

There is no known exploitation of CVE-2025-38146 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38146 and fix it if it is affected.

What it is: CVE-2025-38146 is a critical denial of service vulnerability in Debian Debian Linux, published on 3 Jul 2025. 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-2025-38146 in the wild and no public exploit code.

Affected product: Debian Debian 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-2025-38146/ (Markdown: https://insights.sbomify.com/CVE-2025-38146/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38146
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38146
- OSV: https://osv.dev/vulnerability/CVE-2025-38146

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38146/
Summaries are generated and may contain mistakes; the official description above is the record.