CVE-2026-107102: ERP System Authentication Bypass Flaw

CVE-2026-107102 Overview

CVE-2026-107102 is an authentication bypass vulnerability in an Enterprise Resource Planning (ERP) system. The flaw stems from improper validation of payment callback parameters and inadequate authentication controls on an exposed API endpoint. An unauthenticated remote attacker can manipulate callback parameters to force the application into establishing an authenticated session for an arbitrary user without any valid payment verification. Successful exploitation grants unauthorized access to other user accounts on the targeted system. The vulnerability is categorized under CWE-345: Insufficient Verification of Data Authenticity and was published by CERT-In.

Critical Impact

Remote, unauthenticated attackers can impersonate arbitrary users and gain full access to their ERP accounts and associated business data.

Affected Products

• ERP system identified in CERT-In Vulnerability Note CIVN-2026-0430
• Specific vendor and product details: Not Available in NVD metadata
• Refer to the CERT-In advisory for the authoritative list of affected versions

Discovery Timeline

• 2026-10-07 - CVE-2026-107102 published to NVD
• 2026-10-07 - Last updated in NVD database
• Refer to CERT-In CIVN-2026-0430 for additional disclosure details

Technical Details for CVE-2026-107102

Vulnerability Analysis

The ERP application exposes an API endpoint that processes payment callback data from an external payment flow. The endpoint trusts user-supplied parameters without verifying their authenticity or cryptographic integrity. When the endpoint receives a crafted callback, it treats the request as a legitimate successful payment confirmation and provisions an authenticated session for the user identifier contained in the request. No valid payment transaction, signature, or server-side state verification is required. This allows attackers to pivot a payment-processing control into a full authentication bypass.

Root Cause

The root cause is insufficient verification of data authenticity on the payment callback handler [CWE-345]. The application does not validate callback origin, does not verify a shared secret or HMAC signature from the payment provider, and does not correlate the callback with a pending server-side transaction record. Authentication state is derived directly from attacker-controllable input rather than from a trusted authentication event.

Attack Vector

Exploitation requires only network access to the exposed API endpoint. The attacker crafts an HTTP request that mimics a payment provider callback and includes the target user identifier in the vulnerable parameter. The server processes the forged callback, issues a session token tied to the target account, and returns it to the attacker. No credentials, user interaction, or prior access are required.

No verified proof-of-concept code is publicly available. See CERT-In CIVN-2026-0430 for vendor-coordinated technical details.

Detection Methods for CVE-2026-107102

Indicators of Compromise

• Unexpected successful authentication events for user accounts without a preceding login or multi-factor challenge.
• Payment callback requests originating from IP ranges that do not belong to the configured payment provider.
• Session tokens issued immediately after callback requests that lack a corresponding server-side payment transaction record.
• Access to sensitive ERP modules from new IP addresses or user-agents immediately after a payment callback event.

Detection Strategies

• Correlate payment callback API hits with internal payment transaction state and alert when a callback has no matching pending transaction.
• Validate that payment callbacks carry a verifiable signature from the payment provider; alert on any callbacks missing or failing signature validation.
• Deploy web application firewall (WAF) rules that inspect callback parameters for anomalous user identifier values.

Monitoring Recommendations

• Log every call to the payment callback endpoint including source IP, parameters, and resulting session identifier.
• Monitor for sudden spikes in callback traffic or repeated callbacks referencing different user identifiers from the same source.
• Review ERP audit trails for session creation events that are not preceded by a password or SSO login.

How to Mitigate CVE-2026-107102

Immediate Actions Required

• Apply the vendor-supplied patch referenced in CERT-In CIVN-2026-0430 as soon as it is available.
• Restrict network access to the payment callback endpoint to the payment provider's published IP ranges.
• Invalidate active sessions and force re-authentication for all users after patching.
• Audit recent authentication and session creation events for signs of exploitation.

Patch Information

Consult the vendor advisory linked from CERT-In CIVN-2026-0430 for the authoritative patch and version information. At the time of publication, NVD does not list specific fixed versions.

Workarounds

• Enforce HMAC or digital signature validation on all incoming payment callbacks before any session is issued.
• Decouple session issuance from the payment callback flow; require a separate authenticated login after payment confirmation.
• Place the callback endpoint behind an IP allowlist that only permits the payment provider's upstream servers.
• Add rate limiting and anomaly detection to the callback endpoint to slow brute-force enumeration of user identifiers.

# Example nginx IP allowlist for a payment callback endpoint
location /api/payment/callback {
    allow 203.0.113.0/24;    # Payment provider IP range
    deny all;
    proxy_pass http://erp_backend;
}