LOW CVSS 3.7
Published: 2026-07-02

CVE-2026-54891

erlang erlang\/otp Security Advisory (CVE-2026-54891)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-54891?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-54891 impacting erlang erlang\/otp. Evaluated with CVSS Base Score of 3.7 (LOW).

Original NVD Description

Source: NIST NVD
Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability in Erlang/OTP ssl (tls_gen_connection module) allows a network-positioned attacker to inject unauthenticated plaintext that the TLS client application later treats as authenticated server data. The function tls_gen_connection:handle_protocol_record/3 rejects APPLICATION_DATA records that arrive in pre-handshake states when the TLS endpoint acts as a server, but does not apply the same check when the endpoint acts as a client. A network-positioned attacker can send plaintext APPLICATION_DATA records to the client during the handshake. The records are buffered and, once the handshake completes successfully, delivered to the application as if they were authenticated post-handshake data. The attacker cannot observe the client's response or steer the connection, so the impact is limited to blind injection of unauthenticated bytes. The injection window is wider for TLS versions prior to TLS 1.3 than for TLS 1.3. This vulnerability is associated with program file lib/ssl/src/tls_gen_connection.erl. TLS 1.3 is affected starting with OTP 22.0, when TLS 1.3 support was added. This issue affects OTP from OTP 17.0 before OTP 27.3.4.14, from OTP 28.0 before OTP 28.5.0.3, and from OTP 29.0 before OTP 29.0.3, corresponding to ssl from 5.3.4 before 11.2.12.10, from 11.3 before 11.6.0.3, and from 11.7 before 11.7.3. Whether OTP before OTP 17.0, corresponding to ssl before 5.3.4, is affected is unknown.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
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
None (C:N)
No data confidentiality impact
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product erlang / erlang\/otp
Affected Versions *
Weakness Enumeration CWE-924

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-2026-54891 impacting erlang erlang\/otp.

⚡ Nuclei Detection Template (YAML) cve-2026-54891.yaml
id: cve-2026-54891

info:
  name: erlang erlang\/otp - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: low
  description: |
    Automated signature & scanner for CVE-2026-54891 affecting erlang erlang\/otp.
    Evaluation: Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability in Erlang/OTP ssl (tls_gen_connection module) a...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-54891
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
    cvss-score: 3.7
    cve-id: CVE-2026-54891
    cwe-id: CWE-924
  tags: cve,cve-2026-54891,erlang,erlang\/otp,low

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "erlang\/otp"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-54891.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-54891
# Target: erlang erlang\/otp | 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-2026-54891 (erlang erlang\/otp)...")
    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 erlang erlang\/otp 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-2026-54891.sh
# Recommended Remediation & Patching Commands for CVE-2026-54891
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install erlang\/otp 2>/dev/null || \
sudo dnf upgrade erlang\/otp 2>/dev/null || \
sudo yum update erlang\/otp

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

# 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-2026-54891 in erlang erlang\/otp?

Review vendor-specific security notices and update erlang erlang\/otp 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-2026-54891?

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-2026-54891?

CVE-2026-54891 is classified with a CVSS 3.1 Base Score of 3.7 (LOW). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
3.7
LOW SEVERITY
CVE ID CVE-2026-54891
Weakness CWE-924
Vendor erlang
Product erlang\/otp
Published 2026-07-02
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N