Security researchers identified SessionReaper as an improper input validation / nested deserialization weakness in the Commerce REST API that allows unauthenticated actors to take over sessions and execute code. Proofs of concept and working exploit tools have proliferated, and automated scanning is finding thousands of vulnerable instances. Industry telemetry shows large-scale attack attempts, webshell drops, and customer account takeover attempts against unpatched merchants.
Why this matters for online businesses
Magento is the backbone of many online storefronts worldwide. When a remote code execution bug is weaponized:
- Attackers can deploy webshells, modify checkout logic, and inject payment skimmers.
- Customer data including personally identifiable information and order histories may be exposed.
- Fraud, reputational damage, regulatory exposure, and revenue loss can follow quickly.
- Attackers can pivot from a single compromised store to upstream supply chain or partner systems that rely on the same infrastructure.
Immediate actions for Magento/Adobe Commerce operators
- Patch now – apply Adobe’s updates that remediate CVE-2025-54236. If you have a complex environment, prioritize public-facing Commerce REST API endpoints first.
- Block exploit patterns at the edge – deploy WAF rules to intercept known SessionReaper request signatures and anomalous deserialization payloads.
- Hunt for indicators – look for new webshells, suspicious PHP files, unexpected scheduled tasks, and outbound connections to unknown C2 domains.
- Rotate credentials and keys – force password and API key resets for admin and integration accounts after containment.
- Harden access – restrict management interfaces to trusted IPs, enforce phishing-resistant MFA for admin console access, and enable least privilege for integration tokens.
- Isolate compromised hosts – take affected nodes offline into forensics mode, preserve logs, and restore from clean backups.
- Scan dependencies and custom modules – attackers often exploit custom plugins; audit third-party extensions and remove unused modules.
- Validate customer flows – check payment pages and JavaScript served to customers for injection or skimming artifacts.
- Communicate transparently – inform impacted customers and regulators as required by law and policy.
Longer term resilience
- Implement continuous scanning for known CVEs and automated patch orchestration for critical infrastructure.
- Adopt runtime application self-protection and behavior-based detection to spot malicious in-process actions that static checks miss.
- Build a tested incident response playbook for e-commerce compromise scenarios that includes legal, PR, and customer remediation steps.
- Reduce blast radius by segmenting admin, API, and frontend services.
Conclusion
SessionReaper is a timely reminder that patch publication does not equal patch adoption. For e-commerce operators, delayed updates are effectively open invitations to attackers. The exploit impact goes beyond a single store: customer trust, payment integrity, and regulatory compliance are all at stake. If you run Adobe Commerce or Magento Open Source, treat this as an emergency: patch, detect, contain, and validate.
About COE Security
COE Security partners with organizations in financial services, healthcare, retail, manufacturing, and government to secure AI-powered systems and ensure compliance. Our offerings include:
- AI-enhanced threat detection and real-time monitoring
- Data governance aligned with GDPR, HIPAA, and PCI DSS
- Secure model validation to guard against adversarial attacks
- Customized training to embed AI security best practices
- Penetration Testing (Mobile, Web, AI, Product, IoT, Network & Cloud)
- Secure Software Development Consulting (SSDLC)
- Customized CyberSecurity Services
Based on the SessionReaper incidents, COE Security can help the e-commerce and payments sectors specifically by:
- performing emergency Magento/Adobe Commerce patch and configuration audits;
- deploying WAF rule sets tailored to SessionReaper exploit patterns;
- hunting for webshells, skimmers, and persistence mechanisms across storefronts;
- validating checkout integrity to detect injected payment skimmers;
- securing third-party extension inventories and CI/CD pipelines to prevent malicious updates;
- designing rapid containment and customer notification playbooks for regulated environments.
Follow COE Security on LinkedIn for ongoing insights into secure, compliant AI and e-commerce operations – and to stay updated and cyber safe.