# CVE-2024-39535: Junos OS Evolved: ACX 7000 Series: When specific traffic is received in a VPLS scenario evo-pfemand crashes

> An unauthenticated adjacent attacker can crash the packet forwarding engine in specific VPLS configurations, causing a service outage 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-j93h-6wmf-9mh5

## What is CVE-2024-39535?

CVE-2024-39535 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 ACX 7000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).

When a device has a Layer 3 or an IRB interface configured in a VPLS instance and specific traffic is received, the evo-pfemand processes crashes which causes a service outage for the respective FPC until the system is recovered manually.

This issue only affects Junos OS Evolved 22.4R2-S1 and 22.4R2-S2 releases and is fixed in 22.4R3. No other releases are affected.

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

## Which versions are affected by CVE-2024-39535?

It affects 1 product.


Products: Juniper Junos Os Evolved.

## How do I fix CVE-2024-39535?

No fix has been published for CVE-2024-39535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-39535 being exploited?

There is no known exploitation of CVE-2024-39535 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-2024-39535 and fix it if it is affected.

What it is: CVE-2024-39535 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-2024-39535 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-2024-39535/ (Markdown: https://insights.sbomify.com/CVE-2024-39535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39535
- OSV: https://osv.dev/vulnerability/CVE-2024-39535

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-39535/
Summaries are generated and may contain mistakes; the official description above is the record.