CVE-2026-6223: BiHayat App Authentication Bypass Vulnerability

CVE-2026-6223 Overview

CVE-2026-6223 is an authentication bypass vulnerability in the Bahçelievler Municipality BiHayat App. The flaw stems from improper restriction of excessive authentication attempts [CWE-307], allowing attackers to perform brute-force login attacks over the network without account lockout or rate limiting.

The issue affects BiHayat App versions from 2.1.7 through 07092026. According to the disclosure, the vendor was contacted early about this issue but did not respond. No patched build has been published as of NVD publication.

Critical Impact
Unauthenticated attackers can brute-force user credentials over the network, gain access to citizen accounts, and abuse municipal services with high impact on confidentiality and integrity.

Affected Products

Bahçelievler Municipality BiHayat App version 2.1.7
Bahçelievler Municipality BiHayat App versions between 2.1.7 and 07092026
Bahçelievler Municipality BiHayat App version 07092026

Discovery Timeline

2026-09-07 - CVE-2026-6223 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-6223

Vulnerability Analysis

The BiHayat App exposes an authentication endpoint that does not restrict the number of failed authentication attempts against a given account or source. Attackers can iterate through candidate credentials without triggering lockouts, throttling, or CAPTCHA challenges.

Because the attack vector is network-based and requires no privileges or user interaction, an attacker can script credential-stuffing or brute-force campaigns against the mobile application backend at high volume. Successful login yields full account access within the municipal service platform.

Root Cause

The root cause is a missing or improperly implemented control for excessive authentication attempts, mapped to [CWE-307]. The backend does not enforce per-account or per-IP counters, exponential backoff, or lockout thresholds on failed login submissions. This leaves the login flow susceptible to automated password guessing and credential replay from known breach corpora.

Attack Vector

An attacker interacts with the BiHayat App authentication API over the network, submitting repeated login attempts for a target account or a list of accounts. Since there is no rate limiting, the attacker can use large wordlists or breached credential databases. Once valid credentials are identified, the attacker authenticates as the victim and accesses personal data and transactional functions within the app.

No public proof-of-concept exploit code is available. Refer to the Siber Güvenlik Notification TR-26-1014 for the official advisory.

Detection Methods for CVE-2026-6223

Indicators of Compromise

High volumes of failed authentication requests to the BiHayat App backend from a single source IP or distributed set of IPs.
Successful logins immediately following bursts of failed attempts against the same account.
Authentication events from geolocations or user agents inconsistent with the account holder's normal pattern.

Detection Strategies

Ingest BiHayat App authentication logs into a centralized analytics platform and alert on failure-to-success ratios that exceed baseline thresholds.
Correlate repeated login failures across accounts from shared infrastructure to identify credential-stuffing campaigns.
Flag account access from new devices or ASN ranges that follow a spike in failed authentication attempts.

Monitoring Recommendations

Monitor authentication API endpoints for request rate anomalies and non-human request cadence.
Track account lockout, password reset, and MFA challenge volumes as leading indicators of active brute-force activity.
Retain authentication telemetry for forensic review, including source IP, user agent, timestamp, and outcome.

How to Mitigate CVE-2026-6223

Immediate Actions Required

Restrict or proxy access to the BiHayat App authentication endpoint through a web application firewall that enforces rate limiting.
Notify users to enable multi-factor authentication where supported and to change reused passwords.
Monitor for suspicious authentication traffic patterns and block offending source addresses.

Patch Information

No vendor patch has been published. The disclosure notes that Bahçelievler Municipality did not respond to the researcher's outreach. Track the Siber Güvenlik Notification TR-26-1014 advisory for updates on any future fix release.

Workarounds

Place the authentication API behind a rate-limiting reverse proxy or API gateway that enforces per-account and per-IP thresholds.
Deploy CAPTCHA or challenge-response mechanisms on the login flow to break automated attack tooling.
Enforce account lockout after a defined number of consecutive failed attempts, with exponential backoff for retry windows.
Require multi-factor authentication for account access to reduce the impact of successful credential guessing.

bash

# Configuration example: NGINX rate limiting for a login endpoint
http {
    limit_req_zone $binary_remote_addr zone=login_zone:10m rate=5r/m;

    server {
        location /api/auth/login {
            limit_req zone=login_zone burst=5 nodelay;
            limit_req_status 429;
            proxy_pass http://bihayat_backend;
        }
    }
}