SAP warns of maximum severity 'OVERPASS' kernel vulnerability

CVE-2026-44756 is a critical (CVSS 10.0) memory-safety flaw — a classic buffer overflow (CWE-120) — in the Extended Passport Protocol (EPP) processing library of SAP Kernel, the core runtime underlying SAP NetWeaver components (SAP's advisories tie the issue to SAP Kernel and the NetWeaver Message Server). An unauthenticated remote attacker can trigger it by sending a crafted network request containing a malformed EPP header to a system that processes EPP traffic. The malformed header causes undefined behavior and abnormal program termination, and SAP's maximum-severity rating plus vendor coverage of the flaw indicate it can enable unauthenticated remote code execution with high impact on confidentiality, integrity, and availability. Any organization running the affected SAP Kernel/NetWeaver components — essentially typical ABAP-stack SAP deployments — is exposed until patched. No public proof-of-concept is known, the flaw is not in CISA KEV, EPSS estimates only a 0.3% chance of exploitation within 30 days (25th percentile), and fixes shipped in SAP's September 2026 Security Patch Day.

Do: Apply the SAP Kernel and NetWeaver Message Server fixes released in SAP's September 2026 Security Patch Day (per the 2026-011 advisory covering this flaw), since specific fixed version numbers are not listed in the available data. As interim mitigation, restrict network access to SAP kernel and message-server services to trusted internal networks and identify any SAP instances exposed to the internet. Check SAP's advisory for the exact patch levels applicable to your kernel releases and prioritize externally reachable systems.

SAP Commerce Cloud allows an unauthenticated attacker to abuse a default authentication client and submit specially crafted input to certain functions lacking sufficient validation. Successful exploitation could enable arbitrary code execution and compromise internal components, resulting in high impact on confidentiality, integrity, and availability of the application.

SAP NetWeaver Message Server does not sufficiently validate the authenticity of internal application server components when they register with the service (CWE-308). An unauthenticated attacker with network access to the affected service can send a crafted registration request to add or impersonate an application server component. Once registered, the attacker can potentially perform unauthorized actions within the SAP application environment, resulting in a high impact on confidentiality, integrity, and availability — reflected in the critical CVSS 9.8 score. Any organization running SAP NetWeaver deployments that rely on the Message Server is affected; the source data does not specify exact affected version ranges. There is no evidence of active exploitation, no public proof-of-concept, and the issue is not in CISA KEV, with EPSS assigning only a ~0.3% 30-day exploitation probability; a fix shipped in SAP's September 2026 Security Patch Day (a release that also patched other critical flaws, including the separately reported 'OVERPASS' SAP Kernel issue).

Do: Apply the SAP NetWeaver Message Server fix from the September 2026 SAP Security Patch Day (referenced as advisory 2026-011) as a priority, since the flaw is unauthenticated and network-triggerable; check SAP's portal for the corrected builds applicable to your release, as no specific version numbers were provided in the source data. Until patching, restrict network access to the Message Server (typically TCP 36xx, e.g., 3600) to trusted application server hosts and internal networks, and verify no message server listener is reachable from the internet. Monitor SAP security notes for updates, as no public exploit exists today.