CRITICAL CVSS 9.8
Published: 2026-02-18

CVE-2026-1435

graylog graylog Security Advisory (CVE-2026-1435)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-1435 impacting graylog graylog. Evaluated with CVSS Base Score of 9.8 (CRITICAL).

Original NVD Description

Source: NIST NVD
Not properly invalidated session vulnerability in Graylog Web Interface, version 2.2.3, due to incorrect management of session invalidation after new logins. The application generates a new 'sessionId' each time a user authenticates, but does not invalidate previously issued session identifiers, which remain valid even after multiple consecutive logins by the same user. As a result, a stolen or leaked 'sessionId' can continue to be used to authenticate valid requests. Exploiting this vulnerability would allow an attacker with access to the web service/API network (port 9000 or HTTP/S endpoint of the server) to reuse an old session token to gain unauthorized access to the application, interact with the API/web, and compromise the integrity of the affected account.

📊 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
None (UI:N)
Zero human interaction required
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 graylog / graylog
Affected Versions 2.2.3
Weakness Enumeration CWE-613

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-2026-1435 impacting graylog graylog.

⚡ Nuclei Detection Template (YAML) cve-2026-1435.yaml
id: cve-2026-1435

info:
  name: graylog graylog - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-1435 affecting graylog graylog.
    Evaluation: Not properly invalidated session vulnerability in Graylog Web Interface, version 2.2.3, due to incorrect management of session invalidation after new ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-1435
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-1435
    cwe-id: CWE-613
  tags: cve,cve-2026-1435,graylog,graylog,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "graylog"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-1435.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-1435
# Target: graylog graylog | CVSS: 9.8 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-1435 (graylog graylog)...")
    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 graylog graylog scope (2.2.3).")
        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-2026-1435.sh
# Recommended Remediation & Patching Commands for CVE-2026-1435
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install graylog 2>/dev/null || \
sudo dnf upgrade graylog 2>/dev/null || \
sudo yum update graylog

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

# 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
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❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-1435 in graylog graylog?

Review vendor-specific security notices and update graylog graylog 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-2026-1435?

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-2026-1435?

CVE-2026-1435 is classified with a CVSS 3.1 Base Score of 9.8 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.8
CRITICAL SEVERITY
CVE ID CVE-2026-1435
Weakness CWE-613
Vendor graylog
Product graylog
Published 2026-02-18
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H