ZeroHour

CVE-2026-44756

mass

Unauthenticated buffer overflow in SAP Kernel Extended Passport (EPP) processing

CVSS 3.1
10.0 critical
EPSS
<1%p25
Published
()
Modified
AI analysis

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.

What to 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.

Affected
SAP Kernel (Extended Passport Protocol (EPP) processing library)
SAP NetWeaver (kernel components, including Message Server, per SAP's 2026-011 advisory)
Estimated exposure
mass≈100,000+ SAP systems plausibly affected (EPP/kernel ships with virtually all ABAP-stack NetWeaver deployments; public scans have historically shown tens of… — The vulnerable EPP library is part of SAP Kernel, which is deployed across SAP's roughly 400,000-customer install base with multiple systems per customer, and public internet scans have repeatedly found tens of thousands of exposed SAP…

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

A memory safety vulnerability exists in the Extended Passport Protocol (EPP) processing library. Under specific conditions, an unauthenticated attacker could exploit a crafted network request containing a malformed EPP header, potentially resulting in undefined behavior and abnormal program termination. Successful exploitation may have a high impact on the confidentiality, integrity, and availability of the application.

Weakness
CWE-120
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

In the news

SAP Patches Maximum Severity “Overpass” Flaw

Onapsis warns over 10,000 internet-facing SAP systems may be exposed to maximum-severity unauthenticated RCE flaw CVE-2026-44756 in SAP Extended Passport.

Onapsis Research Labs discovered CVE-2026-44756, a memory corruption flaw in SAP Extended Passport (EPP) processing caused by missing boundary validation during deserialization. The bug is reachable from the SAP GUI and RFC layers, is remotely exploitable without authentication by default, and could let attackers run arbitrary OS commands with SAP administrative privileges. No active exploitation was observed at publication. Onapsis also flagged critical S4GET bug CVE-2026-58240 (CVSS 9.8) in the S/4HANA Message Server, credential disclosure CVE-2026-76969 in SAP CAP, and improper access control CVE-2026-66768 in NetWeaver.

SAP warns of maximum severity 'OVERPASS' kernel vulnerability

SAP's September 2026 patches fix maximum-severity kernel flaw CVE-2026-44756 (OVERPASS), letting unauthenticated attackers execute commands on 10,000+ internet-facing SAP systems.

SAP's September 2026 Patch Tuesday addresses 20 vulnerabilities, headlined by CVE-2026-44756, a buffer overflow in the Extended Passport Protocol (EPP) library of the SAP Kernel dubbed OVERPASS by Onapsis researchers. Unauthenticated attackers can gain administrative command execution via SAP Internet Communication Manager; Onapsis counted more than 10,000 internet-facing SAP systems. SAP also fixed CVE-2026-58240 (S4GET), a critical missing-authentication flaw in the NetWeaver Message Server enabling unauthenticated remote code execution as <sid>adm. Since November 2021, CISA has added 14 SAP flaws to its actively exploited list, three abused by ransomware gangs.

SAP Patches Critical Extended Passport Processing Vulnerability

SAP patches CVSS 10.0 flaw CVE-2026-44756 (OVERPASS) enabling unauthenticated RCE in S/4HANA and NetWeaver, plus three other criticals; no in-the-wild exploitation reported.

CVE-2026-44756 is a CVSS 10.0 memory corruption flaw in Extended Passport (EPP) deserialization, triggered when a user session opens across web, SAP GUI, and RFC vectors. Exploitation yields command execution as the SAP OS account, database credential and password hash recovery, session reading, and data or binary modification; affected products include S/4HANA, ERP/ECC, NetWeaver, Web Dispatcher, and BW/4HANA. Three other criticals were patched: CVE-2026-58240 (S4GET, missing authentication affecting all S/4HANA 2025 and earlier releases), CVE-2026-76969 (CAP credential disclosure), and CVE-2026-66768 (NetWeaver access control). Onapsis and SAP report no indicators of in-the-wild exploitation.

2026-011: Critical Vulnerabilities in SAP Kernel and NetWeaver Message Server

SAP patched two critical flaws, OVERPASS (CVE-2026-44756, CVSS 10.0) and S4GET (CVE-2026-58240), allowing unauthenticated attackers to execute OS commands on SAP hosts.

On SAP's September 2026 Security Patch Day, SAP released Security Notes 3747649 and 3759472 fixing two critical unauthenticated remote vulnerabilities found by Onapsis. CVE-2026-44756 ('OVERPASS', CVSS 10.0) is a memory corruption flaw in Extended Passport (EPP) deserialisation in the SAP Kernel; CVE-2026-58240 ('S4GET', CVSS 9.8) is a missing authentication check in the NetWeaver Message Server that lets attackers register as trusted cluster nodes. Successful exploitation of either can yield OS command execution as the SAP service account, leading to full system and business data compromise, and CERT-EU urges immediate patching. No in-the-wild exploitation is reported.

SAP Patches CVSS 10.0 Kernel Flaw Enabling Unauthenticated Remote Code Execution

SAP patched CVE-2026-44756 (CVSS 10.0), an unauthenticated kernel memory corruption allowing OS command execution, plus three other critical flaws.

SAP's September security updates include CVE-2026-44756 (OVERPASS, CVSS 10.0), a missing boundary validation during deserialization of Extended Passport (EPP) data in the SAP kernel, enabling unauthenticated attackers to run arbitrary OS commands with SAP administrative privileges. Also patched: CVE-2026-58240 (S4GET, CVSS 9.8), a missing authentication check in SAP NetWeaver Message Server yielding RCE as <sid>adm; CVE-2026-76969 (9.4), credential disclosure in SAP Cloud Application Programming Model multi-tenant apps; and CVE-2026-66768 (9.0), improper access control in SAP NetWeaver SAP GUI for Java. Onapsis, which discovered the flaws, says none have been exploited to date and recommends prioritizing internet-facing SAP systems.

SAP September 2026 Security Update Fixes 4 Critical Vulnerabilities and 15 Other Flaws

SAP's September 2026 Patch Tuesday ships 19 security notes, including four criticals led by a CVSS 10.0 memory-corruption flaw in Extended Passport Processing.

SAP released 19 new Security Notes plus one update, fixing four critical vulnerabilities and 15 additional flaws. The most urgent is CVE-2026-44756 (CVSS 10.0), memory corruption in Extended Passport (EPP) Processing affecting many SAP Kernel and Web Dispatcher releases. Other criticals include CVE-2026-58240 (NetWeaver Message Server missing authentication, 9.8), CVE-2026-76969 (credential disclosure in CAP sap/cds-mtxs, 9.4), and CVE-2026-66768 (improper access control in SAP GUI for Java, 9.0). High-severity fixes cover XXE in Integration Suite Trading Partner Management, deserialization in NetWeaver Business Client, and memory corruption in NetWeaver AS for ABAP.

SAP Security Updates September 2026 – Critical Flaws Patched in SAP NetWeaver, Cloud and Extended Passport

SAP's September 2026 Patch Day fixes 19 notes including CVE-2026-44756 (CVSS 10.0), unauthenticated memory corruption in SAP Extended Passport Processing kernels.

SAP shipped 19 new security notes plus one update across NetWeaver, S/4HANA, Integration Suite, Commerce Cloud, and Cloud Application Programming Model. Top issues include CVE-2026-44756 (CVSS 10.0 memory corruption in SAP Extended Passport Processing across many KERNEL and Web Dispatcher versions), CVE-2026-58240 (CVSS 9.8 missing authentication in NetWeaver Message Server), CVE-2026-76969 (CVSS 9.4 credential disclosure in CAP library sap/cds-mtxs), and CVE-2026-66768 (CVSS 9.0 access control flaw in SAP GUI for Java). No exploitation is reported; organizations running affected kernels are urged to patch urgently.