CVE-2026-48011: Shopware Admin Username Enumeration via Timing Attack

Technical summary

CVE-2026-48011 exploits a timing side-channel in Shopware's authentication mechanism prior to versions 6.6.10.18 and 6.7.10.1. The vulnerability stems from CWE-208 (Observable Timing Discrepancy), where the authentication process executes different code paths or delays for valid administrator usernames versus invalid ones. An unauthenticated network attacker can measure response times to infer administrator account existence, effectively enumerating a target's admin user roster. The CVSS 3.1 score of 3.7 (LOW) reflects limited confidentiality impact and the skill required to reliably execute the timing attack.

Business impact

Successful exploitation reveals which accounts on a Shopware instance hold administrative privileges. This intelligence becomes valuable in multi-stage attacks: an attacker gains a confirmed target list for credential-stuffing, phishing, or brute-force campaigns, reducing the attacker's reconnaissance time and improving their targeting accuracy. For businesses, this leakage could expose the identity of key personnel managing the e-commerce platform, potentially enabling social engineering or account takeover attempts. The impact is primarily informational, making this a medium-priority remediation item rather than a critical emergency.

Affected systems

Shopware versions prior to 6.6.10.18 (in the 6.6.x line) and prior to 6.7.10.1 (in the 6.7.x line) are affected. Any organization running an open-source Shopware installation with one of these older versions is vulnerable. Hosted or SaaS offerings may be patched automatically; self-hosted deployments are at higher risk if patch management is not routine.

Exploitability

Exploitation requires network access to the Shopware login endpoint and the ability to perform precise timing measurements across multiple requests—a non-trivial undertaking, reflected in the CVSS metric 'AC:H' (high attack complexity). No authentication is required, and no user interaction is needed. Tools for timing analysis exist in standard security research toolkits, but reliably distinguishing valid admin usernames from false positives demands careful baseline measurement and statistical analysis. The attack is not widely documented in public exploit databases and is not tracked as an active exploitation vector (KEV status: not listed).

Remediation

Upgrade to Shopware 6.6.10.18 or later (for the 6.6 branch) or 6.7.10.1 or later (for the 6.7 branch). These versions implement constant-time authentication checks that prevent timing-based username enumeration. Customers should verify their current version and apply the update according to their patch management schedule.

Patch guidance

1. Identify your Shopware version (visible in the admin panel under System > About). 2. Confirm whether you are on the 6.6.x or 6.7.x line. 3. Download and apply the fixed version from the official Shopware release channel, following the vendor's documented upgrade procedure. 4. Test the update in a staging environment before production deployment to verify compatibility with custom extensions. 5. Review Shopware's release notes for any breaking changes or dependency updates. Because this is a low-severity issue, it can be bundled with regular maintenance windows rather than requiring emergency out-of-band patching.

Detection guidance

Monitor authentication logs for patterns of rapid, unsuccessful login attempts targeting specific usernames, which may indicate timing-based enumeration activity. Intrusion detection systems capable of measuring HTTP response times could potentially flag anomalous timing patterns during login requests. However, definitive detection of timing attacks is challenging without deep analysis. A more practical approach is to ensure you are running a patched version, reducing the window of vulnerability. Periodically verify installed Shopware version against the known-vulnerable list.

Why prioritize this

This vulnerability is low-severity and should be scheduled for patching during normal maintenance cycles rather than treated as an emergency. The attack requires skill and precise measurement, exploitation is not yet publicly documented, and the information leaked (usernames only) does not directly compromise the platform. However, it should not be indefinitely deferred—usernames are valuable reconnaissance data that attackers can weaponize in follow-up attacks. A 60-90 day remediation window is reasonable for organizations with mature patch management; those with ad-hoc patching should prioritize it sooner to reduce cumulative exposure.

Risk score, explained

CVSS 3.1 score of 3.7 (LOW) reflects: Attack Vector Network (exploitable remotely), Attack Complexity High (timing measurements are difficult), Privileges Required None (no auth needed), User Interaction None (passive), Scope Unchanged (no impact outside the vulnerable component), and Confidentiality Low (only usernames disclosed, not credentials). Integrity and Availability are unaffected. The score appropriately captures that this is an information-leakage issue with moderate technical barriers to successful exploitation.

Frequently asked questions