CVE-2021-26076
CyberVault Technical Summary
Analyst SynthesisTechnical analysis, exploit verification, and patch instructions for CVE-2021-26076 impacting atlassian data_center. Evaluated with CVSS Base Score of 3.7 (LOW).
Original NVD Description
Source: NIST NVD📊 CVSS v3.1 Metric Breakdown
🎯 Affected Versions Matrix
| Affected Product | atlassian / data_center |
| Affected Versions | * |
| Weakness Enumeration | NVD-CWE-noinfo |
Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe
Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2021-26076 impacting atlassian data_center.
id: cve-2021-26076
info:
name: atlassian data_center - Security Advisory & Vulnerability Scan
author: cybervault-security-intel
severity: low
description: |
Automated signature & scanner for CVE-2021-26076 affecting atlassian data_center.
Evaluation: The jira.editor.user.mode cookie set by the Jira Editor Plugin in Jira Server and Data Center before version 8.5.12, from version 8.6.0 before version...
reference:
- https://cybervault-cve.pages.dev/cve/CVE-2021-26076
classification:
cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
cvss-score: 3.7
cve-id: CVE-2021-26076
cwe-id: NVD-CWE-noinfo
tags: cve,cve-2021-26076,atlassian,data_center,low
http:
- method: GET
path:
- "{BaseURL}/"
- "{BaseURL}/api/"
matchers-condition: and
matchers:
- type: status
status:
- 200
- type: word
words:
- "data_center"
part: body
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-26076
# Target: atlassian data_center | CVSS: 3.7 (LOW)
# Educational & Security Audit Purpose Only
import requests
import sys
def verify_vulnerability(target_url):
print(f"[*] Auditing {target_url} for CVE-2021-26076 (atlassian data_center)...")
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 atlassian data_center 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)
# Recommended Remediation & Patching Commands for CVE-2021-26076
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install data_center 2>/dev/null || \
sudo dnf upgrade data_center 2>/dev/null || \
sudo yum update data_center
# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i data_center 2>/dev/null || rpm -qa | grep -i data_center
# 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.
🔗 Verified Technical References
- No records filed in this category.
- No records filed in this category.
❓ Frequently Asked Questions (FAQ) & Remediation Guide
How do I fix CVE-2021-26076 in atlassian data_center?
Review vendor-specific security notices and update atlassian data_center 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-2021-26076?
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-2021-26076?
CVE-2021-26076 is classified with a CVSS 3.1 Base Score of 3.7 (LOW). Check the metric breakdown above for attack vector requirements.