MEDIUM CVSS 5.7
Published: 2026-05-08

CVE-2026-42267

kimai kimai Security Advisory (CVE-2026-42267)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-42267?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-42267 impacting kimai kimai. Evaluated with CVSS Base Score of 5.7 (MEDIUM).

Original NVD Description

Source: NIST NVD
Kimai is an open-source time tracking application. From version 2.27.0 to before version 2.54.0, any ROLE_USER can create a tag with a formula string as its name (e.g. =SUM(54+51)) via POST /api/tags and assign it to a timesheet. When an admin exports timesheets to XLSX, ArrayFormatter.formatValue() joins tag names with implode() and returns the result unchanged. OpenSpout promotes any =-prefixed string to a FormulaCell, writing <f>SUM(54+51)</f> into the XLSX archive. Excel evaluates the formula when the file is opened. This issue has been patched in version 2.54.0.

📊 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
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product kimai / kimai
Affected Versions *
Weakness Enumeration CWE-1236

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-2026-42267 impacting kimai kimai.

⚡ Nuclei Detection Template (YAML) cve-2026-42267.yaml
id: cve-2026-42267

info:
  name: kimai kimai - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-42267 affecting kimai kimai.
    Evaluation: Kimai is an open-source time tracking application. From version 2.27.0 to before version 2.54.0, any ROLE_USER can create a tag with a formula string ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-42267
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
    cvss-score: 5.7
    cve-id: CVE-2026-42267
    cwe-id: CWE-1236
  tags: cve,cve-2026-42267,kimai,kimai,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "kimai"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-42267.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-42267
# Target: kimai kimai | CVSS: 5.7 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-42267 (kimai kimai)...")
    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 kimai kimai 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-2026-42267.sh
# Recommended Remediation & Patching Commands for CVE-2026-42267
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install kimai 2>/dev/null || \
sudo dnf upgrade kimai 2>/dev/null || \
sudo yum update kimai

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

# 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

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-42267 in kimai kimai?

Review vendor-specific security notices and update kimai kimai 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-2026-42267?

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-2026-42267?

CVE-2026-42267 is classified with a CVSS 3.1 Base Score of 5.7 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.7
MEDIUM SEVERITY
CVE ID CVE-2026-42267
Weakness CWE-1236
Vendor kimai
Product kimai
Published 2026-05-08
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N