# CVE-2026-72312: octeontx2-af: fix VF bringup affecting PF promiscuous state

> A vulnerability in the Linux kernel allows a virtual function to inadvertently disable the physical function's promiscuous mode, bypassing network monitoring security features.

- **Severity:** High 7.9 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-72312, DEBIAN-CVE-2026-72312, GHSA-87w2-pjwv-62x9, UBUNTU-CVE-2026-72312

## What is CVE-2026-72312?

CVE-2026-72312 is a high-severity vulnerability in Linux, published on 15 Aug 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:

octeontx2-af: fix VF bringup affecting PF promiscuous state

Mbox handling of nix_set_rx_mode for a VF with promiscuous and
all_multi flags set to false causes deletion of the PF's promiscuous
and allmulti MCAM rules. This occurs because the APIs that
enable/disable these rules operate only on the PF, even when the
mbox request is made via a VF interface.

Guard both rvu_npc_enable_allmulti_entry() and
rvu_npc_enable_promisc_entry() disable paths with an is_vf() check so
that a VF bringing up or tearing down its interface cannot inadvertently
clear the PF's MCAM rules.

## Which versions are affected by CVE-2026-72312?


## How do I fix CVE-2026-72312?

Apply the vendor's patch.

## Is CVE-2026-72312 being exploited?

There is no known exploitation of CVE-2026-72312 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72312 and fix it if it is affected.

What it is: CVE-2026-72312 is a high-severity vulnerability in Linux, published on 15 Aug 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-2026-72312 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-2026-72312/ (Markdown: https://insights.sbomify.com/CVE-2026-72312/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72312
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72312
- OSV: https://osv.dev/vulnerability/CVE-2026-72312

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72312/
Summaries are generated and may contain mistakes; the official description above is the record.