CVE-2026-5792: RMC Authentication Bypass Vulnerability

CVE-2026-5792 Overview

CVE-2026-5792 is an authentication bypass by spoofing vulnerability [CWE-290] affecting Hedef Media Promotion Interactive Media Marketing Inc.'s Related Marketing Cloud (RMC) platform. The flaw allows attackers to perform brute force attacks against the authentication mechanism. All RMC versions up to and including build 12052026 are affected.

The vulnerability is exploitable remotely over the network without prior authentication or user interaction. Successful exploitation can compromise both confidentiality and integrity of customer marketing data managed through the RMC platform.

Critical Impact
Remote attackers can bypass authentication through brute force attempts, gaining unauthorized access to marketing automation data and customer records.

Affected Products

Hedef Media Promotion Interactive Media Marketing Inc. Related Marketing Cloud (RMC)
All RMC builds through version 12052026
Customer-facing marketing automation deployments using RMC authentication

Discovery Timeline

2026-06-12 - CVE-2026-5792 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-5792

Vulnerability Analysis

The vulnerability resides in the authentication subsystem of Related Marketing Cloud (RMC). According to the advisory, the authentication mechanism does not adequately distinguish legitimate users from spoofed identities, enabling brute force attacks against credential validation. This category of weakness is tracked as [CWE-290] Authentication Bypass by Spoofing.

An unauthenticated attacker can repeatedly submit credential guesses or forge identity attributes the server uses for authentication decisions. The absence of effective rate limiting, account lockout, or anti-automation controls allows automated guessing at scale. Successful exploitation yields limited confidentiality and integrity impact on user accounts and the marketing data they access.

Root Cause

The root cause is improper validation of authentication claims combined with insufficient anti-brute-force controls. The application accepts repeated authentication attempts without progressively penalizing failures, and the identity verification logic can be tricked by spoofed attributes. Together these weaknesses let attackers iterate through credential or token spaces until a valid combination succeeds.

Attack Vector

The attack vector is the network. An attacker requires no privileges and no user interaction, and the attack complexity is low. The adversary scripts repeated authentication requests against the RMC login endpoint, optionally spoofing identifiers such as client IP, session tokens, or user identity headers to evade weak detection. Once a valid credential is recovered, the attacker authenticates as the targeted user.

No verified public exploit code is available. See the Siber Güvenlik Notification TR-26-0370 for the official advisory.

Detection Methods for CVE-2026-5792

Indicators of Compromise

High volumes of failed authentication events targeting RMC login endpoints from single or distributed source IPs.
Successful logins immediately following clusters of failed attempts for the same account.
Authentication requests with rotating or anomalous User-Agent, X-Forwarded-For, or session identifier values targeting one account.
Logins from geolocations or ASN ranges inconsistent with the legitimate user's historical baseline.

Detection Strategies

Baseline authentication failure rates per account and per source IP, then alert on deviations greater than three standard deviations.
Correlate failed authentication bursts with subsequent successful logins to surface credential-stuffing success.
Flag authentication requests where spoofable identity headers change rapidly within short time windows.
Apply [CWE-290] detection logic to look for inconsistencies between presented identity attributes and server-side session state.

Monitoring Recommendations

Forward RMC web server, WAF, and reverse proxy logs to a centralized SIEM for correlation.
Enable continuous monitoring of administrator and high-privilege RMC account activity.
Track EPSS exploitability trends for CVE-2026-5792 and adjust detection thresholds when the score increases.

How to Mitigate CVE-2026-5792

Immediate Actions Required

Update Related Marketing Cloud to a build released after 12052026 once the vendor publishes a fixed version.
Force a password reset for all RMC accounts and invalidate active sessions to evict any attacker that already brute-forced credentials.
Enable multi-factor authentication on every RMC account, particularly administrators and API integrations.
Restrict access to the RMC authentication endpoint to known corporate IP ranges or a VPN where operationally feasible.

Patch Information

The advisory issued through Siber Güvenlik Notification TR-26-0370 identifies builds through 12052026 as vulnerable. Customers should contact Hedef Media Promotion Interactive Media Marketing Inc. directly for the patched build and apply it across all RMC instances. Validate the fix in a staging environment before production rollout.

Workarounds

Deploy a Web Application Firewall rule that rate-limits requests to the RMC authentication endpoint and blocks IPs exceeding the threshold.
Implement account lockout after a small number of consecutive failed authentication attempts, with exponential backoff.
Add CAPTCHA or proof-of-work challenges on the login flow to defeat automated brute force tooling.
Strip or validate spoofable identity headers such as X-Forwarded-For and X-Real-IP at the edge before they reach the application.

bash

# Example nginx rate-limiting configuration for the RMC login endpoint
http {
    limit_req_zone $binary_remote_addr zone=rmc_login:10m rate=5r/m;

    server {
        location /login {
            limit_req zone=rmc_login burst=5 nodelay;
            limit_req_status 429;
            proxy_pass http://rmc_backend;
        }
    }
}