HIGH CVSS 8.8
Published: 2026-03-30

CVE-2026-33373

synacor zimbra_collaboration_suite Security Advisory (CVE-2026-33373)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-33373?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-33373 impacting synacor zimbra_collaboration_suite. Evaluated with CVSS Base Score of 8.8 (HIGH).

Original NVD Description

Source: NIST NVD
An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A Cross-Site Request Forgery (CSRF) vulnerability exists in Zimbra Web Client due to the issuance of authentication tokens without CSRF protection during certain account state transitions. Specifically, tokens generated after operations such as enabling two-factor authentication or changing a password may lack CSRF enforcement. While such a token is active, authenticated SOAP requests that trigger token generation or state changes can be performed without CSRF validation. An attacker could exploit this by inducing a victim to submit crafted requests, potentially allowing sensitive account actions such as disabling two-factor authentication. The issue is mitigated by ensuring CSRF protection is consistently enforced for all issued authentication tokens.

📊 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
None (PR:N)
Unauthenticated execution
User Interaction
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product synacor / zimbra_collaboration_suite
Affected Versions *
Weakness Enumeration CWE-352

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-2026-33373 impacting synacor zimbra_collaboration_suite.

⚡ Nuclei Detection Template (YAML) cve-2026-33373.yaml
id: cve-2026-33373

info:
  name: synacor zimbra_collaboration_suite - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-33373 affecting synacor zimbra_collaboration_suite.
    Evaluation: An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A Cross-Site Request Forgery (CSRF) vulnerability exists in Zimbra Web Client due...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-33373
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    cvss-score: 8.8
    cve-id: CVE-2026-33373
    cwe-id: CWE-352
  tags: cve,cve-2026-33373,synacor,zimbra_collaboration_suit,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "zimbra_collaboration_suite"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-33373.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-33373
# Target: synacor zimbra_collaboration_suite | CVSS: 8.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-33373 (synacor zimbra_collaboration_suite)...")
    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 synacor zimbra_collaboration_suite 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-2026-33373.sh
# Recommended Remediation & Patching Commands for CVE-2026-33373
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install zimbra_collaboration_suit 2>/dev/null || \
sudo dnf upgrade zimbra_collaboration_suit 2>/dev/null || \
sudo yum update zimbra_collaboration_suit

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

# 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.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-33373 in synacor zimbra_collaboration_suite?

Review vendor-specific security notices and update synacor zimbra_collaboration_suite 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-2026-33373?

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-2026-33373?

CVE-2026-33373 is classified with a CVSS 3.1 Base Score of 8.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.8
HIGH SEVERITY
CVE ID CVE-2026-33373
Weakness CWE-352
Vendor synacor
Product zimbra_collaboration_suite
Published 2026-03-30
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H