# CVE-2026-33783: Denial of service in Junos OS Evolved

> Authenticated attackers can crash the sensor daemon on Juniper PTX routers via specific gRPC queries when SRTE tunnels are provisioned via PCEP, causing persistent service outage.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Apr 2026
- **Updated:** 13 Apr 2026
- **Also known as:** GHSA-q83c-r2qf-fvp6

## What is CVE-2026-33783?

CVE-2026-33783 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 9 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A Function Call With Incorrect Argument Type vulnerability in the sensor interface of Juniper Networks Junos OS Evolved on PTX Series allows a network-based, authenticated attacker with low privileges to cause a complete Denial of Service (DoS).

If colored SRTE policy tunnels are provisioned via PCEP, and gRPC is used to monitor traffic in these tunnels, evo-aftmand crashes and doesn't restart which leads to a complete and persistent service impact. The system has to be manually restarted to recover. The issue is seen only when the Originator ASN field in PCEP contains a value larger than 65,535 (32-bit ASN). The issue is not reproducible when SRTE policy tunnels are statically configured.

This issue affects Junos OS Evolved on PTX Series: 

  *  all versions before 22.4R3-S9-EVO,
  *  23.2 versions before 23.2R2-S6-EVO,
  *  23.4 versions before 23.4R2-S7-EVO,
  *  24.2 versions before 24.2R2-S4-EVO,
  *  24.4 versions before 24.4R2-S2-EVO,
  *  25.2 versions before 25.2R1-S2-EVO, 25.2R2-EVO.

Weakness: CWE-686 (Function Call With Incorrect Argument Type)

## Which versions are affected by CVE-2026-33783?

It affects 1 product.


Products: Juniper Junos Os Evolved.

## How do I fix CVE-2026-33783?

No fix has been published for CVE-2026-33783 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33783 being exploited?

There is no known exploitation of CVE-2026-33783 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-2026-33783 and fix it if it is affected.

What it is: CVE-2026-33783 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 9 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33783 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-2026-33783/ (Markdown: https://insights.sbomify.com/CVE-2026-33783/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33783
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33783
- OSV: https://osv.dev/vulnerability/CVE-2026-33783

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33783/
Summaries are generated and may contain mistakes; the official description above is the record.