CVE-2026-77111: Adobe Commerce Auth Bypass Vulnerability

CVE-2026-77111 Overview

CVE-2026-77111 is an Incorrect Authorization vulnerability [CWE-863] affecting Adobe Commerce, Adobe Commerce B2B, and Magento Open Source. The flaw allows an authenticated attacker with high privileges to bypass security controls and gain unauthorized write access to protected resources. Exploitation does not require user interaction and can be executed over the network. Because the CVSS scope is changed, the impact extends beyond the vulnerable component into other resources managed by the platform.

Critical Impact
An attacker with high-privilege credentials can bypass authorization checks to write unauthorized data and cause a limited availability disruption across Adobe Commerce storefronts, B2B deployments, and Magento Open Source installations.

Affected Products

Adobe Commerce versions 2.4.4 through 2.4.9 (including all patch releases)
Adobe Commerce B2B versions 1.3.3 through 1.5.3 (including all patch releases)
Magento Open Source versions 2.4.7 through 2.4.9 (including all patch releases)

Discovery Timeline

2026-09-08 - CVE-2026-77111 published to NVD
2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-77111

Vulnerability Analysis

The vulnerability stems from an authorization check that fails to correctly validate the privileges of an authenticated user before permitting a write operation. Adobe classifies this weakness under [CWE-863: Incorrect Authorization]. An attacker who already holds high-privilege credentials on the Commerce platform can leverage the flaw to reach functionality or data that should remain outside their permission boundary.

The changed scope in the CVSS vector indicates the impact crosses a trust boundary. A successful bypass in one component affects resources managed by a separate security authority. This behavior is consistent with multi-tenant Commerce deployments, where B2B company accounts, storefronts, and administrative subdomains rely on distinct authorization contexts.

Root Cause

The root cause is an incorrect authorization decision within Adobe Commerce request handling logic. The application evaluates a user's permissions but reaches a permissive outcome when a restrictive one is required. Adobe has not publicly released the affected code path in advisory APSB26-138, and no proof-of-concept exploit is available.

Attack Vector

Exploitation requires network access to the Commerce application and an authenticated session with high privileges, such as an administrative merchant account, an integration API user, or a B2B company administrator. The attacker sends a crafted request to a resource protected by the flawed authorization check. The check accepts the request, allowing the attacker to write data they should not be able to modify and to cause limited disruption to service availability. No user interaction is required.

Because no verified public exploit code is available, technical details of the vulnerable endpoint are not disclosed. Refer to the Adobe Security Advisory APSB26-138 for vendor-provided guidance.

Detection Methods for CVE-2026-77111

Indicators of Compromise

Unexpected write operations performed by administrative or integration accounts against resources outside their normal scope of activity.
Modifications to store configuration, catalog data, or B2B company records that do not correlate with legitimate merchant workflows.
Anomalous REST or GraphQL API calls from high-privilege service tokens targeting endpoints those tokens do not typically use.

Detection Strategies

Audit Adobe Commerce admin action logs and integration API access logs for privilege boundary crossings between merchants, websites, or B2B companies.
Correlate authenticated session activity with source IP reputation and geolocation to identify sessions established from atypical locations.
Compare current Commerce and Magento build versions against the fixed releases listed in advisory APSB26-138 to identify exposed instances.

Monitoring Recommendations

Forward Commerce application logs, web server access logs, and database audit trails to a centralized SIEM for correlation and long-term retention.
Alert on any privilege escalation or authorization failure spikes preceding successful write operations by administrative accounts.
Track API token usage baselines and generate alerts when a token accesses new endpoints or resource identifiers for the first time.

How to Mitigate CVE-2026-77111

Immediate Actions Required

Apply the security update referenced in Adobe advisory APSB26-138 to all affected Commerce, Commerce B2B, and Magento Open Source instances.
Review and rotate credentials for administrative users, integration accounts, and API tokens with elevated privileges.
Enforce least privilege by removing unnecessary administrative roles and disabling unused integration users.

Patch Information

Adobe published fixes as part of security bulletin APSB26-138. Administrators should upgrade to the patched Commerce, Commerce B2B, and Magento Open Source releases identified in that advisory. Verify the deployed version after patching and confirm any custom modules that override authorization logic remain compatible.

Workarounds

Restrict administrative and API endpoint exposure to trusted networks using a web application firewall or reverse proxy allowlist until the patch is applied.
Enable multi-factor authentication for all administrative and B2B company administrator accounts to raise the barrier for credential-based access.
Increase monitoring of high-privilege session activity and manually review sensitive write operations while the patch rollout is in progress.

bash

# Verify installed Adobe Commerce or Magento version
php bin/magento --version

# Apply the vendor patch via Composer (replace with fixed version from APSB26-138)
composer require magento/product-community-edition=<fixed-version> --no-update
composer update

# Recompile and clear cache after upgrade
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento cache:flush