# CVE-2024-39519: Junos OS Evolved: ACX 7000 Series: Multicast traffic is looped in a multihoming EVPN MPLS scenario

> An unauthenticated adjacent attacker can cause a denial of service via multicast traffic loops in specific EVPN MPLS configurations on Juniper ACX routers.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-cr76-625x-q34w

## What is CVE-2024-39519?

CVE-2024-39519 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 11 Jul 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a 

Denial-of-Service (DoS).

On all ACX 7000 Series platforms running 

Junos OS Evolved, and configured with IRBs, if a Customer Edge device (CE) device is dual homed to two Provider Edge devices (PE) a traffic loop will occur when the CE sends multicast packets. This issue can be triggered by IPv4 and IPv6 traffic.

This issue affects Junos OS Evolved: 

All versions from 22.2R1-EVO and later versions before 22.4R2-EVO,

This issue does not affect Junos OS Evolved versions before 22.1R1-EVO.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2024-39519?

It affects 1 product.


Products: Juniper Junos Os Evolved.

## How do I fix CVE-2024-39519?

No fix has been published for CVE-2024-39519 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-39519 being exploited?

There is no known exploitation of CVE-2024-39519 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos Os Evolved

- [CVE-2026-21902](https://insights.sbomify.com/CVE-2026-21902/): Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root (critical 9.3)
- [CVE-2023-28983](https://insights.sbomify.com/CVE-2023-28983/): Junos OS Evolved: Shell Injection vulnerability in the gNOI server (high 8.8)
- [CVE-2025-21599](https://insights.sbomify.com/CVE-2025-21599/): Denial of service in Junos OS Evolved (high 8.7)
- [CVE-2024-47502](https://insights.sbomify.com/CVE-2024-47502/): Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS (high 8.7)
- [CVE-2024-39531](https://insights.sbomify.com/CVE-2024-39531/): Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-39519 and fix it if it is affected.

What it is: CVE-2024-39519 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 11 Jul 2024. 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-2024-39519 in the wild and no public exploit code.

Affected product: Juniper Junos Os Evolved. 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-2024-39519/ (Markdown: https://insights.sbomify.com/CVE-2024-39519/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39519
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39519
- OSV: https://osv.dev/vulnerability/CVE-2024-39519

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From sbomify Insights: https://insights.sbomify.com/CVE-2024-39519/
Summaries are generated and may contain mistakes; the official description above is the record.