HIGH CVSS 7.3
Published: 2026-06-29

CVE-2026-55957

apache tomcat Security Advisory (CVE-2026-55957)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-55957?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-55957 impacting apache tomcat. Evaluated with CVSS Base Score of 7.3 (HIGH).

Original NVD Description

Source: NIST NVD
Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

📊 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
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product apache / tomcat
Affected Versions *
Weakness Enumeration CWE-304

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-2026-55957 impacting apache tomcat.

⚡ Nuclei Detection Template (YAML) cve-2026-55957.yaml
id: cve-2026-55957

info:
  name: apache tomcat - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-55957 affecting apache tomcat.
    Evaluation: Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed at...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-55957
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
    cvss-score: 7.3
    cve-id: CVE-2026-55957
    cwe-id: CWE-304
  tags: cve,cve-2026-55957,apache,tomcat,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "tomcat"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-55957.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-55957
# Target: apache tomcat | CVSS: 7.3 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-55957 (apache tomcat)...")
    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 apache tomcat 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-2026-55957.sh
# Recommended Remediation & Patching Commands for CVE-2026-55957
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install tomcat 2>/dev/null || \
sudo dnf upgrade tomcat 2>/dev/null || \
sudo yum update tomcat

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

# 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-2026-55957 in apache tomcat?

Review vendor-specific security notices and update apache tomcat 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-2026-55957?

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-2026-55957?

CVE-2026-55957 is classified with a CVSS 3.1 Base Score of 7.3 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.3
HIGH SEVERITY
CVE ID CVE-2026-55957
Weakness CWE-304
Vendor apache
Product tomcat
Published 2026-06-29
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L