CVE-2026-76958: SAP Integration Suite XXE Vulnerability

CVE-2026-76958 Overview

CVE-2026-76958 is an XML External Entity (XXE) vulnerability in SAP Integration Suite. The flaw exists because certain internal components fail to sufficiently validate XML documents accepted from untrusted sources [CWE-611]. An authenticated attacker with low privileges can submit crafted XML payloads containing malicious external entity declarations. Successful exploitation exposes sensitive file contents through monitoring or logging output and can trigger resource exhaustion.

Critical Impact
Authenticated attackers can read sensitive files from the SAP Integration Suite server and cause partial availability degradation through XXE payload processing.

Affected Products

SAP Integration Suite (internal components performing XML parsing)
Refer to SAP Note #3792978 for the affected version list
SAP Security Patch Day advisory covers concurrent SAP product fixes

Discovery Timeline

2026-09-08 - CVE-2026-76958 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-76958

Vulnerability Analysis

The vulnerability stems from an XML parser configuration that resolves external entity declarations in documents received from untrusted sources. When an attacker submits an XML payload referencing an external entity, the parser dereferences the entity and includes remote or local resource contents in the parsed document. SAP Integration Suite subsequently exposes the resolved content through monitoring or logging output, giving the attacker read access to sensitive files on the underlying host.

The issue also enables denial-of-service through entity expansion. Recursive or oversized entity references consume memory and CPU during parsing, producing limited availability impact. Integrity remains untouched because the parser only reads external resources rather than modifying application state. The scope change reflects that an attacker acting within the Integration Suite tenant can reach data owned by the underlying host or other components.

Root Cause

The root cause is missing hardening of the XML parser used by the affected internal components. The parser accepts DOCTYPE declarations and resolves external entities by default. Secure XML processing requires explicitly disabling DOCTYPE, external general entities, and external parameter entities. Without those settings, any XML input becomes a file-read primitive constrained only by the process account permissions.

Attack Vector

An attacker authenticated to SAP Integration Suite submits a crafted XML payload to an endpoint that forwards the document to a vulnerable internal component. The payload defines an external entity pointing at a local file such as /etc/passwd, an internal configuration file, or an internal HTTP endpoint. The XML parser resolves the entity during processing. The resolved content is written to monitoring output, logs, or response fields accessible to the attacker.

A verified code example is not available. Refer to the SAP Note #3792978 for vendor-specific technical detail.

Detection Methods for CVE-2026-76958

Indicators of Compromise

XML payloads containing <!DOCTYPE, <!ENTITY, or SYSTEM declarations submitted to Integration Suite endpoints by low-privilege users
Log or monitoring entries containing unexpected file contents such as /etc/passwd, SAP configuration paths, or credential files
Outbound network connections initiated by SAP Integration Suite processes to attacker-controlled hosts during XML parsing
Elevated memory or CPU consumption on Integration Suite worker processes correlated with inbound XML requests

Detection Strategies

Inspect Integration Suite request bodies at API gateways for DOCTYPE and external entity syntax before they reach internal components
Correlate authenticated user activity with anomalous log output volume or content patterns
Baseline outbound network flows from SAP Integration Suite hosts and alert on connections that deviate from known integration endpoints

Monitoring Recommendations

Forward SAP Integration Suite application, audit, and monitoring logs to a centralized SIEM for content inspection
Alert on log entries where user-supplied XML content is echoed alongside filesystem paths or credential material
Monitor process-level file access on Integration Suite hosts for reads of sensitive files by the Java runtime

How to Mitigate CVE-2026-76958

Immediate Actions Required

Apply the fix documented in SAP Note #3792978 as the primary remediation
Review the SAP Security Patch Day bulletin for related fixes released in the same cycle
Audit accounts with access to Integration Suite endpoints and revoke unnecessary low-privilege access
Review recent logs and monitoring output for unexpected filesystem content that may indicate prior exploitation

Patch Information

SAP has published remediation guidance in SAP Note #3792978. Customers must authenticate to the SAP support portal to retrieve version-specific patch instructions and affected component identifiers. Coordinated release information is available on the SAP Security Patch Day portal.

Workarounds

Restrict access to XML-accepting Integration Suite endpoints using network segmentation and identity policies until patches are applied
Deploy Web Application Firewall rules that block XML payloads containing DOCTYPE or external entity declarations
Disable or filter monitoring and logging outputs that echo raw XML content back to authenticated users
Enforce least privilege on the Integration Suite service account to limit the filesystem scope reachable through entity resolution

bash

# WAF rule concept: block XML payloads containing DOCTYPE declarations
# Adjust for your gateway syntax (ModSecurity example)
SecRule REQUEST_HEADERS:Content-Type "@rx xml" \
  "chain,id:1076958,phase:2,deny,status:400,msg:'Blocked XXE pattern (CVE-2026-76958)'"
SecRule REQUEST_BODY "@rx (?i)<!DOCTYPE|<!ENTITY|SYSTEM\s+\"" "t:none"