CVE-2026-44756: EPP Library Buffer Overflow Vulnerability

CVE-2026-44756 Overview

CVE-2026-44756 is a memory safety vulnerability in the Extended Passport Protocol (EPP) processing library. An unauthenticated remote attacker can send a crafted network request containing a malformed EPP header to trigger undefined behavior and abnormal program termination. The flaw is classified under [CWE-120] as a classic buffer copy without size validation.

The issue affects components addressed by SAP security guidance and carries the maximum CVSS base score, reflecting network attack vector, no privileges required, and scope change with high impact across confidentiality, integrity, and availability.

Critical Impact
Unauthenticated remote attackers can trigger memory corruption in the EPP processing library, causing service disruption and potentially compromising confidentiality, integrity, and availability of downstream systems.

Affected Products

Components processing Extended Passport Protocol (EPP) headers, as referenced in SAP Note 3747649
Refer to the SAP Security Patch Day advisory for the authoritative product and version list
Specific affected product versions were not enumerated in the NVD entry at publication

Discovery Timeline

2026-09-08 - CVE-2026-44756 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-44756

Vulnerability Analysis

The vulnerability resides in the parsing logic of the Extended Passport Protocol (EPP) processing library. The library fails to properly validate the size or structure of fields within an inbound EPP header before copying them into a fixed-size memory region. A malformed header can therefore overflow the intended buffer boundary.

Because the flaw is exposed over the network and requires no authentication or user interaction, an attacker only needs the ability to reach the listening service. The scope-change classification indicates that a successful exploit affects resources beyond the vulnerable component itself.

Successful exploitation causes undefined behavior and abnormal termination of the process. Depending on runtime conditions and memory layout, an attacker may also be able to influence execution flow, extending the impact from denial of service to potential code execution.

Root Cause

The root cause is a classic buffer copy without validation of input length, matching [CWE-120]. The EPP parser trusts attacker-controlled length or delimiter fields inside the header and writes past the destination buffer boundary. This corrupts adjacent memory structures used by the receiving process.

Attack Vector

Exploitation is performed over the network. The attacker sends a single crafted request containing a malformed EPP header to any endpoint that processes EPP traffic. No credentials, prior access, or victim interaction are required. See SAP Note 3747649 for authoritative technical detail.

No public proof-of-concept or exploit code was available in the enriched data at the time of writing.

Detection Methods for CVE-2026-44756

Indicators of Compromise

Unexpected crashes, core dumps, or restarts of processes handling EPP traffic
Malformed or oversized EPP header fields recorded in application or protocol logs
Inbound network traffic to EPP-processing services from unusual or untrusted source addresses
Repeated connection resets or protocol errors preceding a service outage

Detection Strategies

Deploy network intrusion detection signatures that flag EPP headers exceeding expected field length or containing invalid delimiters
Correlate application crash events with preceding network traffic to the affected service
Monitor for anomalous parent-child process behavior originating from EPP-handling services, which may indicate post-exploitation activity
Ingest application and network telemetry into a centralized analytics platform to identify low-and-slow probing patterns

Monitoring Recommendations

Continuously monitor availability metrics of services processing EPP traffic and alert on unplanned restarts
Track outbound connections from EPP-processing hosts to detect follow-on command-and-control activity
Alert on stack traces referencing the EPP parser in crash reports and application logs
Baseline normal EPP request sizes and flag statistical outliers for investigation

How to Mitigate CVE-2026-44756

Immediate Actions Required

Apply the vendor-supplied patch referenced in SAP Note 3747649 as the primary remediation
Inventory all systems exposing EPP-processing endpoints and prioritize internet-facing instances
Restrict network access to EPP services to trusted management networks until patches are deployed
Review crash and application logs for indicators of prior exploitation attempts

Patch Information

SAP has published remediation guidance through SAP Note 3747649 and its monthly SAP Security Patch Day release. Administrators should authenticate to the SAP support portal to obtain the specific patched component versions applicable to their deployment and follow the vendor's recommended upgrade path.

Workarounds

Block inbound access to EPP protocol ports at perimeter and internal firewalls where the service is not required
Place a protocol-aware proxy or web application firewall in front of exposed endpoints to filter malformed EPP headers
Disable EPP processing on components that do not require it, following vendor guidance
Segment EPP-processing hosts into isolated network zones to limit blast radius if exploitation succeeds

bash

# Example: restrict EPP service access to trusted management subnet
# Replace <EPP_PORT> and <TRUSTED_SUBNET> with values from your environment
iptables -A INPUT -p tcp --dport <EPP_PORT> -s <TRUSTED_SUBNET> -j ACCEPT
iptables -A INPUT -p tcp --dport <EPP_PORT> -j DROP