CVE-2026-109805
Received Received - Intake

Weak HMAC Cryptography in SAP NetWeaver and ABAP Platform Enables Privilege Escalation

Publication date: 2026-11-10

Last updated on: 2026-11-10

Assigner: SAP SE

Description
Due to a weak HMAC cryptography calculation when receiving an RFC callback in SAP NetWeaver and ABAP Platform (Application Server ABAP), an authenticated attacker with high privileges and access to a network segment between application servers on an SAP system could intercept network communication between application servers and change the identity of the caller, enabling the execution of unauthorized function calls on the target server with escalated privileges leading to High impact on Confidentiality, Integrity, and Availability of the application.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-11-10
Last Modified
2026-11-10
Generated
2026-11-10
AI Q&A
2026-11-10
EPSS Evaluated
N/A
NVD
CVE-2026-109805
EUVD
EUVD-2026-120703

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
sap netweaver *
sap abap_platform *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-328 The product uses an algorithm that produces a digest (output value) that does not meet security expectations for a hash function that allows an adversary to reasonably determine the original input (preimage attack), find another input that can produce the same hash (2nd preimage attack), or find multiple inputs that evaluate to the same hash (birthday attack).

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability involves a weak HMAC cryptography calculation in SAP NetWeaver and ABAP Platform when receiving an RFC callback. An authenticated attacker with high privileges and network access between application servers could intercept communication, alter caller identity, and execute unauthorized function calls with escalated privileges.

Detection Guidance

Detecting this vulnerability requires monitoring network traffic between SAP application servers for unusual RFC callback communications with weak HMAC signatures. Inspect SAP logs for unauthorized function calls or privilege escalations. Use network sniffing tools like Wireshark to analyze SAP-specific protocols (e.g., DIAG, RFC) for tampered identity fields or missing HMAC integrity checks.

Impact Analysis

It can lead to unauthorized access, data breaches, and system compromise. Attackers could gain control over application servers, steal sensitive data, modify system behavior, or disrupt services, affecting confidentiality, integrity, and availability of the application.

Compliance Impact

This vulnerability could violate compliance requirements by enabling unauthorized data access or modification. GDPR and HIPAA mandate strict data protection; a breach could result in legal penalties, reputational damage, and loss of trust due to compromised confidentiality and integrity.

Mitigation Strategies

Apply SAP Security Note 3786876 immediately to patch the weak HMAC cryptography issue in SAP NetWeaver and ABAP Platform. Restrict network access between application servers to trusted segments only. Monitor for unauthorized function calls or privilege escalation attempts.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-109805. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart

Security Radar

News mentioning this vulnerability
Loading related security news...