SAP warns of maximum severity 'OVERPASS' kernel vulnerability

Summary

SAP has released its September 2026 security updates, addressing 20 vulnerabilities, including a critical memory corruption flaw in the SAP Kernel, tracked as CVE-2026-44756 and named OVERPASS. This vulnerability, a buffer overflow in the Extended Passport Protocol (EPP) processing library, allows unprivileged attackers to execute arbitrary commands with administrative privileges on vulnerable SAP hosts. Additionally, CVE-2026-58240, a critical missing authentication flaw in the SAP NetWeaver Message Server, allows unauthenticated attackers to gain full remote code execution.

Full text

SAP warns of maximum severity 'OVERPASS' kernel vulnerability By Sergiu Gatlan September 8, 2026 10:55 AM 0 SAP has addressed 20 vulnerabilities across multiple products in its September 2026 security updates, including a maximum-severity memory corruption flaw in the SAP Kernel code. Tracked as CVE-2026-44756 and dubbed OVERPASS by Onapsis security researchers who reported it, the vulnerability stems from a classic buffer overflow weakness in the Extended Passport Protocol (EPP) processing library. Successful exploitation lets unprivileged threat actors run arbitrary commands on vulnerable SAP hosts with administrative privileges, leading to full compromise of the underlying SAP processes and business data. The flaw can be exploited over SAP Internet Communication Manager (ICM), the networking component of the SAP Application Server that connects the SAP System (SAP NetWeaver Application Server) to the Internet via HTTP, HTTPS, and SMTP. According to Onapsis' estimates, more than 10,000 Internet-facing SAP systems use the vulnerable component and are potentially exposed to attacks exploiting the CVE-2026-44756 flaw. "A targeted search using high-fidelity fingerprints identifies more than 10,000 unique Internet-facing IP addresses presenting an SAP web interface reachable from the public Internet, and that figure is conservative," Onapsis CTO JP Perez-Etchegoyen said on Tuesday. "It counts only HTTP-reachable systems and materially undercounts the SAP Web Dispatcher, which proxies its backend and returns no distinguishing SAP banner on its root path, making it structurally hard for Internet-wide scanners to attribute." S4GET, logic flaw in SAP's NetWeaver Message Server Today, SAP also addressed CVE-2026-58240, a critical missing authentication vulnerability in the SAP NetWeaver Message Server named S4GET by Onapsis Research Labs. After successful exploitation, unauthenticated attackers can access the entire SAP system cluster and execute malicious payloads and arbitrary commands remotely across the network. "The flaw is triggered through the same public port that every SAP GUI client connects to, so it cannot be firewalled away without breaking the end-user logon," Onapsis security researcher Pablo Artuso explained. "Exploitation requires no credentials, no certificate, and no pre-existing misconfiguration. A successful attack yields full remote code execution as <sid>adm, the OS-level user that runs SAP, on every application server in the cluster." Last month, SAP fixed another maximum-severity vulnerability (CVE-2026-58231) in the Commerce Cloud cloud-based e-commerce platform, which threat intelligence company Defused flagged as actively exploited in attacks days after it was patched. Since November 2021, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added 14 SAP security flaws to its list of actively exploited vulnerabilities, including three that were abused by ransomware gangs. SAP is a German multinational software company that reported total revenues exceeding €36 billion in fiscal year 2025 and provides services to 99 of the 100 largest companies worldwide. Once attackers have valid credentials, only 37% of their actions are blocked Overall prevention scores can hide what happens after initial access. Once attackers are using valid credentials, prevention drops sharply.The Blue Report 2026 measures defenses technique by technique across 338 million simulations run in customer production environments. Get the report Related Articles: SAP warns of critical flaws in NetWeaver and Commerce CloudWebinar: The forgotten Google Workspace access that can lead to a breachMassive Microsoft 365 outage causes auth issues, service failuresNearly 22,000 Microsoft Exchange servers vulnerable to hijack attacksMax severity SAP Commerce Cloud flaw now targeted in attacks

Indicators of Compromise

• cve — CVE-2026-44756
• cve — CVE-2026-58240
• cve — CVE-2026-58231

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