# CVE-2025-39810: bnxt_en: Fix memory corruption when FW resources change during ifdown

> A memory corruption vulnerability in the Linux kernel bnxt_en driver allows attackers to cause denial of service or execute code when firmware resources change during interface shutdown.

- **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:** 16 Sep 2025
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-67431, AZL-71206, BELL-CVE-2025-39810, DEBIAN-CVE-2025-39810, GHSA-rv8g-6vr7-cv64, ROOT-OS-DEBIAN-11-CVE-2025-39810, ROOT-OS-DEBIAN-12-CVE-2025-39810, ROOT-OS-DEBIAN-13-CVE-2025-39810, ROOT-OS-UBUNTU-2204-CVE-2025-39810, ROOT-OS-UBUNTU-2404-CVE-2025-39810, UBUNTU-CVE-2025-39810

## What is CVE-2025-39810?

CVE-2025-39810 is a high-severity memory corruption vulnerability in Linux kernel, published on 16 Sep 2025. 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:

bnxt_en: Fix memory corruption when FW resources change during ifdown

bnxt_set_dflt_rings() assumes that it is always called before any TC has
been created.  So it doesn't take bp->num_tc into account and assumes
that it is always 0 or 1.

In the FW resource or capability change scenario, the FW will return
flags in bnxt_hwrm_if_change() that will cause the driver to
reinitialize and call bnxt_cancel_reservations().  This will lead to
bnxt_init_dflt_ring_mode() calling bnxt_set_dflt_rings() and bp->num_tc
may be greater than 1.  This will cause bp->tx_ring[] to be sized too
small and cause memory corruption in bnxt_alloc_cp_rings().

Fix it by properly scaling the TX rings by bp->num_tc in the code
paths mentioned above.  Add 2 helper functions to determine
bp->tx_nr_rings and bp->tx_nr_rings_per_tc.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2025-39810?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-39810?

Apply the vendor's patch.

## Is CVE-2025-39810 being exploited?

There is no known exploitation of CVE-2025-39810 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-2025-39810 and fix it if it is affected.

What it is: CVE-2025-39810 is a high-severity memory corruption vulnerability in Linux kernel, published on 16 Sep 2025. 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-2025-39810 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-2025-39810/ (Markdown: https://insights.sbomify.com/CVE-2025-39810/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39810
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39810
- OSV: https://osv.dev/vulnerability/CVE-2025-39810

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39810/
Summaries are generated and may contain mistakes; the official description above is the record.