CVE-2026-56450: AIL 2FA Authentication Bypass Vulnerability

CVE-2026-56450 Overview

CVE-2026-56450 is a two-factor authentication (2FA) brute-force vulnerability in the AIL Framework, an open-source analysis platform for information leaks. The application failed to throttle repeated failed attempts to verify a one-time password (OTP) code during the second authentication stage. An attacker who already passed the password step could submit unlimited OTP guesses and brute-force the six-digit code. Successful exploitation bypasses the second authentication factor and grants unauthorized account access. The weakness maps to [CWE-307: Improper Restriction of Excessive Authentication Attempts].

Critical Impact
An attacker holding valid credentials can defeat the 2FA control through unrestricted OTP guessing, leading to full account takeover of AIL Framework accounts, including administrator roles.

Affected Products

AIL Framework (ail-project/ail-framework)
AIL versions prior to commit d3a394fe68fd5aeee86f3a3c91d4a0350f91e974
Deployments using 2FA/OTP for the AIL web interface

Discovery Timeline

2026-06-22 - CVE-2026-56450 published to NVD
2026-06-22 - Last updated in NVD database

Technical Details for CVE-2026-56450

Vulnerability Analysis

The AIL Framework web interface implements 2FA as a second step after password authentication. The verification handler accepts OTP submissions without tracking failed attempts per user and without enforcing a lockout after repeated failures. An attacker who completed password authentication reaches the OTP prompt and can iterate through the OTP keyspace at request speed. Because OTP codes are typically six digits, a sustained brute-force run has a high probability of guessing a valid code before it rotates. The flaw is a missing security control rather than a cryptographic weakness in OTP generation.

Root Cause

The var/www/blueprints/root.py route handling 2FA verification lacked per-user failed-attempt counters and time-based lockouts. No state was persisted between OTP submissions, so each guess was evaluated in isolation. The patch introduces constants OTP_MAX_FAILED_ATTEMPTS = 30 and OTP_FAILED_TIMEOUT = 3600, blocking verification for one hour after 30 failed submissions and clearing the counter on success. Administrator recovery actions allow purging lockouts for legitimate users.

Attack Vector

Exploitation requires network access to the AIL web interface and valid first-factor credentials (for example, stolen or phished username and password). The attacker drives the OTP step programmatically, submitting candidate codes until one validates. User interaction by the targeted account is not required during the brute-force phase.

python

# Source: https://github.com/ail-project/ail-framework/commit/d3a394fe68fd5aeee86f3a3c91d4a0350f91e974
# Security patch in var/www/blueprints/root.py adding 2FA brute-force protection
# LOGS
access_logger = ail_logger.get_access_config()

LOGIN_MAX_FAILED_ATTEMPTS = 5
LOGIN_FAILED_TIMEOUT = 300
OTP_MAX_FAILED_ATTEMPTS = 30
OTP_FAILED_TIMEOUT = 3600

# ============ BLUEPRINT ============

Detection Methods for CVE-2026-56450

Indicators of Compromise

High volume of failed OTP verification requests from a single source IP or session against the AIL 2FA endpoint.
Successful login events immediately preceded by dozens of failed OTP attempts for the same user.
Authenticated sessions originating from IPs or geolocations not previously associated with the user account.
Application logs in access_logger showing rapid sequential POSTs to the 2FA verification route.

Detection Strategies

Parse AIL web access logs for repeated 4xx responses on the OTP verification route grouped by username or session identifier.
Build a rule that fires when the count of failed OTP submissions per user exceeds a threshold (for example, 10) within five minutes.
Correlate password-stage success with subsequent OTP failures to identify post-credential-theft brute-force attempts.

Monitoring Recommendations

Forward AIL Framework web logs to a centralized SIEM or data lake for retention and rule-based alerting.
Alert on any account where OTP verification failures exceed OTP_MAX_FAILED_ATTEMPTS (30) within OTP_FAILED_TIMEOUT (3600 seconds).
Monitor administrator actions that purge OTP lockouts and require justification for each unlock.

How to Mitigate CVE-2026-56450

Immediate Actions Required

Update AIL Framework to a build that includes commit d3a394fe68fd5aeee86f3a3c91d4a0350f91e974 or later.
Force password resets for any accounts that show unexplained successful logins following bursts of failed OTP attempts.
Re-enroll 2FA secrets for users whose accounts may have been brute-forced.
Review administrator accounts for unauthorized access and rotate API tokens or session keys.

Patch Information

The upstream fix is delivered in the AIL Framework security commit. It adds per-user failed-OTP tracking in var/www/blueprints/root.py, blocks OTP verification for one hour after 30 failed attempts, clears the counter after a successful verification, and adds administrator recovery actions in var/www/blueprints/settings_b.py to purge affected lockouts.

Workarounds

Place the AIL web interface behind a reverse proxy that enforces rate limiting on the 2FA verification path.
Restrict network access to the AIL console using a VPN or IP allowlist until the patch is deployed.
Temporarily disable accounts that show indicators of credential compromise.

bash

# Example nginx rate limit for the AIL 2FA verification endpoint
limit_req_zone $binary_remote_addr zone=ail_otp:10m rate=5r/m;

location /2fa {
    limit_req zone=ail_otp burst=5 nodelay;
    proxy_pass http://ail_backend;
}