HIGH CVSS 7.5
Published: 2026-06-09

CVE-2026-45445

openssl openssl Security Advisory (CVE-2026-45445)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-45445 impacting openssl openssl. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD
Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary: Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate / EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's streaming handler flushes the application-supplied IV into the OCB context before processing data; the one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero key-derived offset state left by cipher initialisation, regardless of the caller's IV. If EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at that point and clears the running checksum that should have been accumulated over the plaintext. The resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module boundary.

📊 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
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product openssl / openssl
Affected Versions *
Weakness Enumeration CWE-325

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-2026-45445 impacting openssl openssl.

⚡ Nuclei Detection Template (YAML) cve-2026-45445.yaml
id: cve-2026-45445

info:
  name: openssl openssl - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-45445 affecting openssl openssl.
    Evaluation: Issue summary: When an application drives an AES-OCB context through the
public EVP_Cipher() one-shot interface, the application-supplied
initialisati...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-45445
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2026-45445
    cwe-id: CWE-325
  tags: cve,cve-2026-45445,openssl,openssl,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "openssl"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-45445.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-45445
# Target: openssl openssl | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-45445 (openssl openssl)...")
    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 openssl openssl 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-2026-45445.sh
# Recommended Remediation & Patching Commands for CVE-2026-45445
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install openssl 2>/dev/null || \
sudo dnf upgrade openssl 2>/dev/null || \
sudo yum update openssl

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

# 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-2026-45445 in openssl openssl?

Review vendor-specific security notices and update openssl openssl 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-2026-45445?

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-2026-45445?

CVE-2026-45445 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.5
HIGH SEVERITY
CVE ID CVE-2026-45445
Weakness CWE-325
Vendor openssl
Product openssl
Published 2026-06-09
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N