MEDIUM CVSS 6.5
Published: 2026-04-09

CVE-2026-33783

juniper junos_os_evolved Security Advisory (CVE-2026-33783)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-33783 impacting juniper junos_os_evolved. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
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.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product juniper / junos_os_evolved
Affected Versions *
Weakness Enumeration CWE-686

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-33783 impacting juniper junos_os_evolved.

⚡ Nuclei Detection Template (YAML) cve-2026-33783.yaml
id: cve-2026-33783

info:
  name: juniper junos_os_evolved - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-33783 affecting juniper junos_os_evolved.
    Evaluation: A Function Call With Incorrect Argument Type vulnerability in the sensor interface of Juniper Networks Junos OS Evolved on PTX Series allows a network...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-33783
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 6.5
    cve-id: CVE-2026-33783
    cwe-id: CWE-686
  tags: cve,cve-2026-33783,juniper,junos_os_evolved,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "junos_os_evolved"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-33783.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-33783
# Target: juniper junos_os_evolved | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-33783 (juniper junos_os_evolved)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against juniper junos_os_evolved scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-33783.sh
# Recommended Remediation & Patching Commands for CVE-2026-33783
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install junos_os_evolved 2>/dev/null || \
sudo dnf upgrade junos_os_evolved 2>/dev/null || \
sudo yum update junos_os_evolved

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i junos_os_evolved 2>/dev/null || rpm -qa | grep -i junos_os_evolved

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-33783 in juniper junos_os_evolved?

Review vendor-specific security notices and update juniper junos_os_evolved packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-33783?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-33783?

CVE-2026-33783 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2026-33783
Weakness CWE-686
Vendor juniper
Product junos_os_evolved
Published 2026-04-09
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H