External risk intelligence

SAP NetWeaver ABAP XML Tampering Leading to Unauthorized Access and Disruption.

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2026-44748

The vulnerability affects SAP NetWeaver Application Server ABAP, which is typically deployed in internal corporate networks. While the application can be exposed to the internet, it is often protected behind firewalls or VPNs, and the vulnerability requires an attacker to already possess valid, albeit low-privileged, authenticated access to the system.

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A security issue has been identified in SAP NetWeaver Application Server ABAP and ABAP Platform that could allow an authenticated user to tamper with signed documents, potentially leading to unauthorized access to sensitive data and system disruption. The vulnerability has a high impact on confidentiality, integrity, and availability.

Attackers can alter signed documents.
It impacts sensitive data and system availability.
Confirm relevance and assess potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker with basic access to SAP NetWeaver can create a fake signed message. By sending this modified XML document to the system's verifier, they can trick it into accepting false identity information. This can lead to unauthorized access to sensitive data and disrupt system operations.

Requires authenticated user access.
Verifier accepts a tampered XML document.
Risk of unauthorized data access.

Live Threat

Current exploitation, exposure, and threat context

An authenticated attacker with normal privileges could forge signed XML documents to impersonate legitimate users, potentially granting them unauthorized access to sensitive user data and disrupting system operations. This could affect the confidentiality, integrity, and availability of the application.

Sensitive user data could be exposed.
Tampered identity information could be accepted.
Unauthorized access to the application could occur.

Operational Fix

Recommended remediation, mitigation, and detection steps

SAP NetWeaver Application Server ABAP and ABAP Platform owners are responsible for managing this vulnerability. The first step is to identify all instances of the affected technology, determine their business criticality and network exposure, and then locate the accountable system owners. Remediation planning should be based on the assessed risk and potential impact to sensitive user data and system operations.

Identify and confirm accountable system owners.
Verify system reachability and business criticality.
Plan risk-based remediation and vendor coordination.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Free EASM Trial See How Signal Works

Frequently asked questions

What is SAP NetWeaver Application Server ABAP?

SAP NetWeaver Application Server ABAP is the foundational platform that runs SAP business applications. It provides the runtime environment for developing and executing ABAP programs, which manage core enterprise data, business processes, and user identities across an organization's internal systems.

What does CWE-347 mean for CVE-2026-44748?

CWE-347 refers to Improper Verification of Cryptographic Signature. In the context of CVE-2026-44748, this means the software fails to properly check that a signed XML document is authentic. Because the system trusts these signatures without sufficient validation, it can be tricked into accepting tampered identity information as legitimate.

How does an attacker trigger this vulnerability?

An attacker needs existing, low-privileged authenticated access to the SAP environment to initiate the attack. They use this access to obtain a valid signed message and modify the XML content. The bug is not triggered by unauthenticated users or by sending unmodified, standard documents; the system must specifically accept the forged XML as a trusted, signed input.

Do I need to worry if my SAP instance is internal?

While Halo Surface Signal notes this software is often hosted internally and protected by VPNs, the risk remains. Because the vulnerability requires an authenticated attacker, an internal-only status does not eliminate the threat from compromised local accounts or malicious insiders who can leverage their valid credentials to manipulate system identity verification.

What should I do first to manage this issue?

Start by auditing your environment to create a complete inventory of all SAP NetWeaver ABAP instances. Once located, coordinate with your system owners to document the business criticality of each instance. Use this information to prioritize which systems require immediate attention based on the sensitivity of the data they process and their overall impact on your business operations.

References

me.sap.com/notes/3746332

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.